Has Bin Laden struck again?

At least 190 people were killed in train bomb attacks during Madrid's morning rush hour.

The ten co-ordinated blasts tore through trains and stations along a commuter line in the Spanish capital, injuring more than 1,200 ahead of this weekend's general election.

At first, the government blamed Spain's worst terrorist attack on the Basque separatist group Eta. ''This is mass murder,'' said Prime Minister Jose Maria Aznar after an emergency Cabinet meeting, vowing to hunt down the attackers and ruling out talks with Eta.

''No negotiation is possible or desirable with these assassins who so many times have sown death all around Spain."

However, the scale of the attack, absence of a phone warning and lack of any claim of responsibility prompted speculation that al-Qaida was responsible.

The London-based Arabic language Al Quds newspaper said it had received an e-mail from a group representing Osama bin Laden's terror network claiming responsibility for the explosions.

Spain's Interior Minister,Angel Acebes, later revealed that an Islamic tape had been found with detonators in a stolen van recovered near Madrid.

The van was discovered in the town of Alcala de Henares - where three of the four bombed trains originated. The other train passed through the town.

Mr Acebes said the tape - one of seven discovered in the van - contained verses of the Koran, in Arabic. "Because of this, I have just given instructions to the security forces not to rule out any line of investigation," he said.

However, the minister added that Eta remained the "main line of investigation".

A political group close to Eta has denied that it carried out the attacks.

Tony Blair led British condemnation of the bombings.''This terrible attack underlines the threat that we all continue to face from terrorism in many countries and why we must all work together internationally to safeguard our peoples against such attacks and defeat terrorism," he said.

Last night, a steady stream of taxis carrying mourners arrived at a convention centre where bodies were being taken. Forty coroners were working to identify remains.

The Interior Ministry said tests showed the explosives used in the attacks were a kind of dynamite normally used by Eta, which wants an independent Basque state in northern Spain and south-west France.

A source at Mr Aznar's office said the explosives were a material called titadine, a kind of compressed dynamite found in an Eta van-bomb intercepted last month as it headed for Madrid.

But a US intelligence official said: "It's too early to tell who planted the bombs. We're not ruling anything out.''

Arnold Otegi, a leader of the Basque party linked to Eta which has been banned from the election, suggested the bombings were the work of ''Arab resistance''.

The bombs started exploding at 6.39am GMT in a commuter train arriving at Atocha station, a bustling hub for underground, commuter and long-distance trains. Blasts also rocked trains at two other stations.

Worst hit was a double-decker train at the El Pozo station, where two bombs killed 70 people.

The ten bombs were detonated by remote control. Police staged three other controlled blasts of bombs or suspicious objects.

The bodies of the dead, some with their mobile phones ringing unanswered as frantic relatives tried to contact them, were carried away by rescue workers.

The wounded, faces bloodied, sat on curbs as buses were pressed into service as ambulances.

The attack dwarfed the deadliest outrage blamed on Eta until now - 21 killed in a Barcelona supermarket explosion in 1987 - and shocked officials who had insisted recently that the group was on the ropes.

Only the bombing of a Pan Am jetliner over Lockerbie in 1988 that killed 270 has caused greater terror attack casualties in Europe

The attack horrified Spain during the build-up to Sunday's general election, which Premier Aznar's party is now expected to win comfortably. Campaigning was called off and three days of mourning were declared.