Europese regeringsleiders geschokt door bomaanslag in Madrid (en)

European leaders have expressed shock and outrage at bomb attacks in Spain that have killed at least 170 people in the capital Madrid and left hundreds more injured.

At least four bombs exploded at three stations in Madrid this morning, the first at 7:40am, well into rush hour in the Spanish capital.

At least two controlled explosions have also been reported.

According to Radiotelevisión Española the bombs were packed in backpacks and placed in the interior of the trains and exploded as the trains were close or in the stations.

Eyewitness reports speak of the trains being packed with commuters. Witnesses also say the platforms were also packed at the three stations targeted, Atocha (a hub station), El Pozo and Santa Eugenea both in the south of the city.

Interior minister Angel Acebes speaking at Atocha, the scene of the first two explosions, called for calm so that the emergency services could operate properly.

But in an emotional atmosphere there was also a measure of defiance.

"I have absolutely no doubt that the people who carried out these attacks will be found, taken into custody and will pay dearly for these crimes they have committed", he said.

No one has yet claimed responsibility for the blasts - which came just days before Spain goes to the polls in a general election - although the government has pointed to ETA.

ETA - a Basque separatist guerrilla group - is listed by both the EU and the United States as a terrorist organisation.

Outrageous, unjustified and unjustifiable

European Parliament President Pat Cox described the attacks as "the worst act of terror in the history of Spain, the worst act of terror in memory in any European Union state".

He added that it was "an outrageous, unjustified, and unjustifiable attack on the Spanish people and on Spanish democracy".

And, referring to the forthcoming elections - where Basque separatism will be a key issue - he said, "What happened today is a declaration of war on democracy ... let Sunday give the answer that Spanish democracy is strong".

Irish Taoiseach and current President of the European Council, Bertie Ahern, said that the bombings were "an attack on the democratic process and cannot be justified by any political cause".

British foreign secretary Jack Straw described the bombings as "a disgusting assault on the very principle of European democracy".

And European Commission President Romano Prodi told a news conference that "we are all victims of this attack".

He announced he would be taking part in a silent demonstration of solidarity at the Schuman roundabout in Brussels at 13:00 today.

Flags will be flown at half-mast at the Commission building and in all Commission representations in the EU.

Spain's political parties have ceased campaigning for Sunday's elections, according to the BBC, but there is currently no indication as to whether the poll will be postponed.

Spain's train operator RENFE have said that anybody worried that their friends or relatives may be involved should contact them at 00 34 900 200 222.