CARACAS, Venezuela -- Venezuelan troops fired tear gas and shotgun pellets to clear anti-government demonstrators outside a Caracas police station on Sunday, a day after President Hugo Chavez's government seized control of the police from the city's mayor, a foe of the populist president.

Dozens of armored military vehicles, backing several hundred national guard troops, were deployed across the capital to enforce the government takeover of the metropolitan police force from Caracas Mayor Alfredo Pena, a measure denounced by the opposition as illegal.

Clouds of gas scattered demonstrators, including families and children, protesting outside the Mariperez police station after troops moved to prevent a small group of opposition leaders from entering the installation, Reuters reported.

Late Sunday, a firebomb exploded in the parking lot of the private television news station Globovision, setting fire to three cars but causing no casualties, police and firefighters said.

No one claimed responsibility but opposition leaders have blamed government supporters for past bomb and grenade attacks against anti-Chavez media, labor and business organizations.

Interior Ministry officials on Saturday ordered the 8,000-member Caracas city police force to report to the government to guarantee order because it said a strike by some officers had hampered operations. But the opposition condemned the takeover as an unconstitutional attack on the mayor's authority.

Chavez, a former paratrooper elected in 1998 who faces fierce opposition to his leftist rule, said the move was aimed at resolving a policing crisis. He also accused his opponents of manipulating officers for political purposes.

"The metropolitan police have fallen into anarchy.

... It's become an obligation of the national executive as this has turned into a problem of security and public order," Chavez said during a weekly broadcast on Sunday.

The takeover has fueled tensions between Chavez and his opponents even as international negotiators tried to broker a peaceful solution to the nation's long-running political war.

Frequent protests and street clashes have rattled the world's fifth-largest oil exporter since April when Chavez survived a brief coup.

--- Impasse Within Police Ranks --- After the short-lived uprising, Chavez has battled growing resistance to the self-styled "revolution" he says addresses poverty and inequality. The opposition, which accuses him of driving Venezuela into economic ruin and dictatorship, is pressing for an immediate referendum on his rule.

Troops were deployed on Saturday after gunfights broke out between police officers loyal to the government and those opposed to the seizure. Though the government has named a new police chief, it was unclear how many officers would back the takeover; the previous chief, Henry Vivas, said he remained in command.

But the police takeover could in effect neutralize an armed force potentially hostile to the government. The action comes after several street battles between the metropolitan police and militant supporters of the president, during which at least two people were killed and dozens injured.

Several hundred protesters joined the Caracas mayor on Sunday outside the Mariperez police station, the headquarters of the motorized unit, to protest the takeover.

But troops repeatedly prevented Pena from entering the building "I was elected by popular vote. I have every right to visit those officers," Pena told Globovision television news.

Earlier, demonstrators, waving flags and banners, chanted: "Hear U.S. soldiers; this is your fight too," as some tried to hand carnations to the soldiers lined up before them.

The latest political skirmish comes as organization of American States Secretary General Cesar Gaviria struggles to negotiate a deal on an electoral solution to the country's political conflict.

Chavez accuses political foes like Pena of plotting to overthrow him and has dismissed opposition calls for him to resign. He has urged his opponents to wait until August 2003 when the constitution allows a binding vote on whether he should stay in power.

But opposition leaders -- a loose alliance of unions, business leaders, political parties and rebel military officers -- have threatened to call a national strike if their call for an immediate poll is blocked.