Spain's interior minister said Sunday a videotape has been discovered claiming Al Qaeda (search) carried out the Madrid terrorist attacks and threatening more, but that he could not verify the veracity of the claim.

Interior Minister Angel Acebes (search) said a man identifying himself as the military spokesman of Al Qaeda in Europe claimed the group was responsible for the attacks Thursday that killed 200 people and wounded 1,500.

"We declare our responsibility for what happened in Madrid exactly 21/2 years after the attacks on New York and Washington," said the man, according to a government translation of the tape, which was recorded in Arabic. "It is a response to your collaboration with the criminals Bush and his allies."

Prime Minister Jose Maria Aznar (search) has been a staunch supporter of the U.S.-led war in Iraq.

A London-based Arabic newspaper had earlier received a claim of responsibility in Al Qaeda's name; but the government has been reluctant to blame the Islamic group, saying the Basque separatist group ETA (search) was also a suspect. ETA denied responsibility.

Speaking at a hastily called post-midnight news conference at the interior ministry, Acebes said authorities could not confirm the claim was genuine. He said the videotape was discovered after an Arabic-speaking man called a Madrid TV station and said where it could be found.

A statement from the ministry said the speaker was identified as Abu Dujan al Afghani. Acebes said the man was not known to law enforcement authorities in Spain, and that they were checking the tape's authenticity.

The man threatened further attacks in the video.

"This is a response to the crimes that you caused in the world, and specifically in Iraq and Afghanistan, and there will be more if God wills it," the man said, according to the Spanish government's translation.

Thursday's attacks in Madrid came just days before Sunday's general elections in Spain. At demonstrations Saturday, some protesters said they believed the ruling party was playing down the possible link between the bombings and Spain's role in Iraq, fearing it would hurt the party's chances in the election.