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

Interior Minister Angel Acebes said a man identifying himself as the military spokesman of Al-Qaida 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 2.5 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 has been a staunch supporter of the U.S.-led war in Iraq.

Authorities in Spain also arrested three Moroccans and two Indians on Saturday in connection with the bombings, yet another indication of a possible Islamic link to the attack.

The announcement of the arrests, by Acebes, came just hours before polls were to open today in general elections weighed down by debate over who carried out Europe's deadliest terrorist attack in 15 years.

Acebes said the five suspects were all arrested around Madrid. A spokesman for the Moroccan government identified the three Moroccans as Jamal Zougam, 30; Mohamed Bekkali, 31, a mechanic; and Mohamed Chaoui, 34. All three are from northern Morocco, but the government gave no further details about them.

"One might have connections with Moroccan extremist groups. But it is still very early to establish to what degree," Acebes said. He did not name any group.

Asked whether the Basque separatist group ETA is still considered a suspect, Acebes said: "We must not rule anything out." ETA denied responsibility.

The five suspects were arrested after a gym bag packed with explosives and a cell phone was discovered on one of the four bombed rush-hour trains, the minister said. The attacks killed 200 people and injured 1,500.

A London-based Arabic newspaper had earlier received a claim of responsibility in al-Qaida's name; but the government has been reluctant to blame the Islamic group.

Speaking at a hastily called post-midnight news conference at the interior ministry, Acebes said authorities could not confirm the videotaped 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.

Just months ago, a taped threat thought to be from al-Qaida terror chief Osama bin Laden had included Spain among countries that could be attacked "at the appropriate time and place."

A confirmed Islamic extremist involvement in the Madrid bombings could play into the hands of Aznar critics who opposed sending 1,300 peacekeepers to Iraq.

"If it was al-Qaida, this was a reprisal for sending troops to Iraq, where we have no business being," said Damian Garcia, whose 86-year-old father died in the bombings.

The government had sought to dampen such speculation. Acebes said earlier Saturday that autopsies conducted on victims showed no signs of suicide bombings - a hallmark of Islamic militants.

Pressure mounted for answers. A crowd outside the Popular Party headquarters chanted, "We want the truth before voting."

Aznar's hand-picked candidate to succeed him, Mariano Rajoy, charged that the rally violated a law banning political demonstrations on the day before an election.

The death of a man in a hospital overnight pushed the toll from the attack up to 200 Saturday. Of the 1,511 injured, 266 remained hospitalized - with 17 in critical condition.

Since the Sept. 11, 2001, attacks in the United States, only the Bali bombing in Indonesia in October 2002 was deadlier, with 202 people dead. The Madrid attack was Europe's deadliest since the 1988 bombing of a Pan Am jetliner over Lockerbie, Scotland, killed 270 people.

A steady stream of hearses carried coffins in and out of Madrid's biggest funeral home, Tanatorio Sur. The sprawling red-brick building normally has plenty of room, but was still overwhelmed Saturday. For lack of space, the coffins of a couple killed in the attacks were placed in a room normally used for staff meetings.

"My son. Why?" repeatedly sobbed one elderly woman, leaning on relatives.