Spaniards were defiant in the face of terrorism last night, taking to the streets in their millions in protest against the Madrid bombings which have sent shock waves around the world.

As the vast crowds gathered, the 199th victim died - a seven-month-old girl. The baby's mother is also in hospital and her father is missing.

Of the 1,400 people who were injured, 366 were still in hospital and 59 were in a critical condition. Two unnamed Britons were among the casualties - a man and a woman - but their injuries were described as "not serious".

Last night, Prime Minister Jose Maria Aznar and political leaders from other European countries led a sea of humanity snaking its way down Madrid's main boulevard toward Atocha station, one of three bombed on Thursday.

Huge rallies also got underway in Barcelona, Seville, Valencia and many other Spanish cities and towns, including in the Basque region.

Ten bombs exploded in several trains and stations in the centre of the Spanish capital during commuter rush hour.

Speculation has raged over who was responsible, with Prime Minister Aznar insisting all lines of inquiry are open.

"We will bring the guilty to justice," he said. "No line of investigation is going to be ruled out."

On Thursday, he accused the Basque separatist group Eta of carrying out the attacks, but a claim of responsibility came from an offshoot of the al Qaida network.

The London-based Arabic language Al Quds newspaper said it received an e-mail from the Brigade of Abu Hafs al-Masri, who claimed its "death squad" had penetrated "one of the pillars of the crusader alliance".

"This is part of settling old accounts with Spain, the crusader, and America's ally in its war against Islam," it said.

Referring to the Spanish Prime Minister, the statement asked: "Aznar, where is America? Who will protect you, Britain, Japan, Italy and others from us?"

Spanish police also discovered a van on the outskirts of the city with detonators and an Arabic language tape with verses from the Koran.

Yesterday, Home Secretary David Blunkett warned that the bombings proved the "tentacles of terrorism" were reaching out to every corner of the world.

Metropolitan Police Commissioner Sir John Stevens said London was still on the second highest level of alert.

He said: "All our efforts must go into making sure something like this does not happen in Britain."

Spain has been regarded as a potential target for Islamic terrorists because of Mr Aznar's strong support for Britain and America in the war against Iraq.

The Prince of Wales sent a message of sympathy to Spain's King Juan Carlos. He said: "I was utterly horrified to hear of the dreadful bomb attacks.

"My heart goes out to you and all the Spanish people at this time of profound grief and my prayers are with you."

At noon yesterday, Spaniards across the country observed several minutes of silence.

As the emergency services continued to work their way through the rubble and twisted metal at the bombing scenes, Deputy Justice Minister Rafael Alcala said 84 bodies had yet to be identified.