The bombs were found in the German cities of Dortmund and Koblenz on July 31 with German Criminal Police Office (BKA) chief Jörg Ziercke saying that were arranged to explode simultaneously at 2:30 p.m. Neither of the bombs was detonated.

"It's more likely than unlikely that there was a terrorist background," Ziercke told a news conference in Wiesbaden. If the around 25-kilo (55-lb.) suitcase bombs had exploded they would have lead to "a fireball" in the train carriages and an "indeterminate number of injured and possible deaths," he said.

Speaking in Berlin Friday, German Interior Minister Wolfgang Schäuble also warned that Germany should brace itself for similar attempts. "Unfortunately, we must assume that the danger of a repeat of these attempted attacks."

The discovery of the two bombed sparked a series of scares at railway stations across Germany with parts of the central station in Düsseldorf sealed off Friday after a suspicious suitcase was found. Officials in Düsseldorf later gave the all-clear, saying it had been a false alarm.

50,000 euro reward

The BKA press conference had been called to report on the investigation into the discovery of the suitcases which contained bottles of petrol, propane gas and a detonating device in trains at Dortmund and Koblenz railway stations. Speaking to reporters, the BKA chief said that it was unlikely that the bombs found at the two German railway stations represented an attempt to blackmail the German rail operator, Deutsche Bahn.

German police are searching for these two men

The investigators released images obtained from surveillance cameras of two suspects in the possible plot and announced that there would be a reward of 50,000 ($64,195) euros for any information which would lead to the capture of the two young men in the grainy photos, who were both described as being from "southern countries."
 
Terror plot "highly likely"
 
The BKA suggested that Germany was being targeted for attacks possibly by a terrorist organization operating in the country. If the explosive devices had been detonated, their size and construction would have created devastation and death on a scale reminiscent of the July 7, 2005 attacks on the London transport system, according to a report in the Süddeutsche Zeitung newspaper.
 
Both of the suitcases discovered on July 31 contained gas cylinders rigged up to an ignition mechanism and had been left in two regional trains which usually run at the height of the commuter rush hour. The suitcases were discovered by rail staff when the trains terminated at the two hub stations. The construction of the devices and the potential impact the explosions would have had suggests a sophisticated plot.
 

A German security official with one of the canisters

Investigations by BKA engineers revealed that the bombs were designed so that simultaneous detonation would have been possible and that they would generate "an explosive force so big that the explosion would have reached the dimension of the subway attack on London in the summer of 2005," a high-ranking security source told the newspaper.
 
In the London attacks, 52 people were killed and over 700 were injured when suicide bombers struck on three underground trains and a bus.
 
No Lebanon connection
 
The authorities dismissed claims that the German plot was connected to the on-going instability in Lebanon despite the discovery of a smaller bag within one of the suitcases which was printed with Arab text and comes from a business in the Lebanese capital of Beirut.
 
Many of these bags could have arrived in Germany in the past few months and it was not sufficient evidence to connect the plot to Lebanon, investigators said.
 
The investigation has fired an intense debate in Germany regarding the expansion of video surveillance in railway stations and in trains. Some German states have already taken steps to increase their "big brother" security systems.
 
Debate rages on increased surveillance
 
The conservative-controlled Hamburg state government wants to add more cameras to streets and public places, not just railway stations and trains.

Opinions differ on what measures should be taken

In Brandenburg, Interior Minister Jörg Schönbohm of the Christian Democratic Union (CDU) said that the state was considering limiting surveillance to people getting on and off trains in an attempt to dodge the controversial topic of data protection.
 
However, federal data protection czar Peter Schaar has pleaded for more to be done, with extra staff and cameras placed at all railway stations and on trains to increase security.

See also:

German bombs 'mass murder' bid

BBC News: 18 August 2006

Police are still trying to work out why the devices did not explode

German police have ruled out blackmail as the reason why two bombs were left on trains on 31 July - and now believe it was a failed terror attack.

The bombs were in identical black cases on trains in Dortmund and Koblenz.

They had been timed to explode 10 minutes before the trains arrived, said federal crime chief Joerg Ziercke.

"We are now working on the basis that this was the work of a terrorist group... and was an attempt to kill a large number of people," he said.

Police want to trace two men seen on CCTV wheeling cases at Cologne station.

Initial suggestions that the bombs may have been an attempt to blackmail a train company had been ruled out, Mr Ziercke said.

He said police were working on the theory that the group responsible were based in Germany.

The Arabic note found with one of the bombs lists grocery items

The devices consisted of gas canisters, alarm clocks, wires, batteries and a flammable liquid in soft drink bottles.

A handwritten note in Arabic, listing groceries, a telephone number in Lebanon and packets of starch labelled in Arabic and English, were also found.

Mr Ziercke said up to 100 investigators were trying to work out why the devices failed to detonate. "We still have many unanswered questions," he said.

He appealed to the public for help in tracking down the people who planted the device.

See also:

Germans publish stills of botched terror suspects

Financial Times: August 18 2006
By Bertrand Benoit in Berlin

German investigators on Friday published photographs of two suspects wanted in connection with a botched terrorist attack on regional trains last month that was intended to cause casualties on an “unimaginable” scale.

Wolfgang Schäuble, interior minister, announced fresh security measures in reaction to the attempted attack, including intensified police surveillance of railway stations and luggage searches. He urged regional governments, responsible for police work, and the public to raise their vigilance.

The stills, grabbed from security camera recordings at Cologne’s railway station, showed two men, aged 20 to 30, who investigators said had planted powerful makeshift bombs on two regional trains that passed through the station on July 31.

“We must take these events extremely seriously and, unfortunately, we must assume that there is a danger of a renewed attempt,” Mr Schäuble said. “We cannot afford to be sitting on our hands.”

The bombs – gas containers and fuel bottles packed in suitcases – were found by passengers after they failed to detonate because of what Jörg Ziercke, head of the Federal Criminal Office, called “a construction flaw”.

The detonators showed the bombs were intended to explode simultaneously shortly before the two trains – headed for Koblenz and Dortmund in western Germany – reached their final stop, causing “deaths on a considerable scale”, Mr Ziercke said.

The authorities have offer-ed up to €50,000 ($64,000, £34,000) for information on the men, who it said were being treated as members of a domestic terrorist organisation.

The dark-haired men of medium build are clearly seen on the shots, with one of them wearing a football shirt and cargo pants. The fact they were both carrying several pieces of luggage suggested they might have left the country after planting the bombs, security officials said.

Among items recovered from the suitcases were a pack of starch purchased in an Essen spice shop, a handwritten shopping list in Arabic and a scrap of newspaper, pointing to links with the Lebanon.

News of the aborted attack has caused shock in Germany, where opinion polls show terrorism ranking low on the list of people’s fears and far behind unemployment and declining income.

Since last month’s find, several regional governments have said they wanted to boost video surveillance of stations and other areas. Such plans have failed before over privacy concerns.