Germany releases US attack suspect

Hamburg police raided eight addresses in the city

Police in the north German city of Hamburg have released without charge a man held in connection with the terror attacks on the United States but new arrests have been made in other European cities.

In a joint Belgian-Dutch operation two people were detained in Brussels and four in Rotterdam. All were said to belong to a "radical Islamic movement".

Automatic weapons and ammunition were seized during searches in Brussels. One of the suspects may have been preparing attacks on US targets in Europe, a Belgian police spokeswoman said.

It is not clear if those arrested were linked to Tuesday's attacks.

FBI co-operation

The man released in Hamburg was seized during raids on eight Hamburg addresses on Wednesday night, after an FBI tip-off.

His name and nationality were not released but he was known to have worked at Hamburg airport.

A spokeswoman for the federal prosecutor said he had been released at midnight on Thursday and he was not suspected of any criminal act.

Unconfirmed reports say police in other regions of Germany have been searching property, acting on information from America. FBI agents are now reported to be on their way to Germany to help in the investigations.

Arab students

Three men on the passenger lists of the hijacked aircraft used in Tuesday's attacks were registered as Hamburg residents.

Two of them, Mohammed Atta and Marwan Al-Shehhi, are believed to have lived at one of the addresses searched on during Wednesday's raids in the Harburg part of the city.

They are reported to have lived in Florida from July 2000 to January 2001, where they attended flying school.

Mohammed Atta was registered at a Hamburg address

According to their registration documents, both men came from the United Arab Emirates. They were enrolled as students at the city's technical university taking courses in shipbuilding and electronics.

Their flat had been empty since February this year and police found the rooms had been carefully cleaned - though experts still hope to find traces they left behind.

Federal prosecutors are also trying to hunt down another suspect - a man of Arab origin, known to them by name - and are investigating what they describe as a Hamburg-based terrorist network.

The man would face charges including membership of a terrorist organisation, murder and an attack on air traffic, said chief federal prosecutor Kay Nehm.

Marwan al-Shehhi: also studied at technical university

A statement from Mr Nehm's office said the goal of the network under investigation was to co-operate with like-minded groups to attack the United States "through the destruction of symbolic buildings".

Investigators presume the cell was made up of at least four men of Arab origin.

Suspicions were only raised once the FBI provided information about those on board the hijacked planes.

A Hamburg security chief, Reinhard Wagner, said that aides of the US's most wanted terrorist suspect, Osama Bin Laden, were based in the city, and had possibley acted "as intermediaries for contacts or accommodation".