March 13 (Bloomberg) -- Spain arrested three Moroccans and two Indians in connection with the train-bombing attacks that killed at least 200 people and injured more than 1,500 in Madrid Thursday, said Interior Minister Angel Acebes.

``Some of the arrested could have links with extremist Moroccan groups,'' Acebes said in a press conference tonight, without providing any other details. He didn't say if the suspects were linked to al-Qaeda, which has threatened to target Spain.

The suspects were identified after police recovered an unexploded bomb from the attack containing a cell phone used as a detonator, Acebes said. The suspects were involved in selling counterfeit cell phones and cards to activate the phones and were linked to the device attached to the bomb, he said.

Two Spanish nationals of Indian origin were also being questioned, Acebes said. All the arrests were made in Madrid.

The arrests come a day before general elections in Spain and signal that the attacks may have been linked to threats from Islamic terror groups to avenge retiring Prime Minister Jose Maria Aznar's support for the U.S.-led war on Iraq. Since the attack, Acebes and other government officials have said the primary suspect was the Basque terror group ETA, which has killed more than 800 people, though it rarely targets civilians in mass numbers.

ETA

More than 90 percent of Spaniards opposed the government's support of the war in Iraq and the revelation that the government's position may have contributed to the attack may hurt the ruling Popular Party in voting tomorrow.

Around the time of the attack on Baghdad, the opposition Socialist Party, led by Jose Luis Zapatero, 43, surpassed the Popular Party in an opinion poll for the only time since the PP came to power in 1996.

``It obviously points toward al-Qaeda and that could be potentially damaging for the government,'' said Henrik Lumholdt, chief strategist at Inversis Banco in Madrid.

Erin Healy, a White House spokeswoman, declined to comment tonight on an al-Qaeda connection and whether U.S. agents are cooperating with Spanish authorities. Healy said the U.S. government had been in contact with Spanish officials.

Rush to Judgment

The Popular Party recovered its lead in the polls partly through its success in curtailing ETA attacks. Last month, security forces detained alleged ETA members with a van loaded with more than 1,000 pounds of explosives headed for Madrid. Those arrests came after two alleged ETA activists were caught with luggage filled with explosives in another Madrid train station on Christmas Eve.

``I am still going to vote for the Popular Party,'' said Victor Portillo, 48, who works for a security-services company in Madrid. ``They have been very serious about fighting terrorism and they are going to keep doing it as hard as they can.''

Even with ETA's history, the scale of Thursday's attacks -- which claimed more lives than the Basque group has in more than a decade -- made many Spaniards suspect that the government was rushing to judgment.

Today, thousands of people gathered in front of the PP's Madrid headquarters, shouting, ``Who really did it?'' as riot police tried to control the crowd.

Acebes said tonight that ETA is still considered a suspect.

Gauge the Effect

Mariano Rajoy, 48, who replaced Aznar, 51, as head of the party and is seeking a third term for the ruling PP, went on television to denounce the protest in Madrid and said it was organized by political rivals and designed to exert ``an intolerable pressure'' on voters. No campaigning is allowed on the final day before voting in Spain.

The final opinion polls were published on March 8, three days before the bombing. Rajoy's party was predicted to win with 42 percent of the vote, compared to 38 percent for the opposition Socialists, according to an opinion poll conducted by market research company Sigma Dos for the newspaper El Mundo.

It was published on the latest day surveys could be released under election rules. The survey of 1,000 voting-age Spaniards had a margin of error of plus or minus 3.2 percentage points.

With no polling permitted before the vote, there will be no way to gauge the effect the bombing and arrests will have on voters until after the polls close at 8 p.m. Madrid time tomorrow.

Claim Discounted

Acebes began to acknowledge the possibility of a connection to Islamic terrorists Thursday night when he announced that police had found a van with detonators and a cassette tape in Arabic used for teaching the Koran.

Also on Thursday, a group called Brigades of Martyr Abu Hafs al-Masri sent a letter to an Arab language newspaper in London taking responsibility for the blast in the name of al-Qaeda. Acebes discounted the claim, pointing out that the group had falsely claimed other attacks and even said they caused the blackout on the East Coast of the U.S. in August.

Yesterday, Acebes went on national television to say the government still believed ETA carried out the attacks, even though the type of explosive that caused the blast -- a recent form of Goma Dos, which is manufactured in Spain -- hasn't been used by the group in more than a decade. The detonators found in the van matched those used in the bombings blast and also differed from the type traditionally used by ETA.

At about the same time Acebes spoke yesterday, ETA issued a denial that it was involved in the attacks to Basque newspaper Gara.

To contact the reporter on this story: Andrew Davis in Madrid at abdavis@andrewbdavis.net

Last Updated: March 13, 2004 17:59 EST