PORT-AU-PRINCE, Haiti (AP) -- Two U.N. peacekeepers were wounded in shootouts with supporters of ousted President Jean-Bertrand Aristide in Port-au-Prince and with angry storm survivors in flood-ravaged Gonaives -- the first casualties in the force's 4-month-old mission in Haiti.

An Argentine soldier was shot in the arm Saturday night in Gonaives, officials said Sunday, after protesters outside a Mass for flood victims of Tropical Storm Jeanne accused Haiti's U.S.-backed government of not doing enough to help.

The soldier was shot in the area of Raboteau seaside slum and neighboring Descahos slum, known hangouts for street gangs and flashpoints of violence since rebels overthrew Aristide during a three-week rebellion in February.

On Saturday, after Prime Minister Gerard Latortue and President Boniface Alexandre flew off in a helicopter, people in that neighborhood threw rocks at cars carrying their special Haitian police guards as they drove out of the city, said Col. Adrian Sanchez, the Argentine commander in Gonaives.

The guards opened fire and a 20-year-old man was shot in the leg, sustaining a serious injury, he said. U.N. troops evacuated him to the capital where he was in stable condition, Sanchez said.

Saturday night, U.N. peacekeepers came under fire in the same area and an Argentine soldier was hit in the arm. None of the soldiers saw who fired because the city has no electricity, and it was possible the attackers mistook the peacekeepers for the special police, Sanchez said.

In the capital, meanwhile, people were on alert Sunday for more violence.

Heavy gunfire erupted in Port-au-Prince on Saturday as about 150 Brazilian troops using armored vehicles and 150 Haitian police in trucks rolled into the volatile slum of Bel Air, where armed young men have been demanding the return of Aristide from exile, Brazilian Lt. Col. Ezequiel Izaias said.

Peacekeepers "came under heavy fire and they returned fire," said U.N. spokesman Toussaint Kongo-Doudou.

The Brazilian soldier was wounded in the foot -- the first casualty among some 3,000 peacekeepers, Kongo-Doudou said. He said it appeared some gunmen were wounded, but it was unclear how many.

Troops and police arrested more than 60 people suspected of attacking them, Kongo-Doudou said. Police on the edge of Bel Air were seen holding suspects to the ground at gunpoint and tying their hands with rope.

The clashes came a day after the beheaded bodies of a father and son were found in the Port-au-Prince slum of La Saline.

Elsewhere, Argentine peacekeepers on Saturday guarded the cathedral in northwestern Gonaives city from more than 100 protesters, who shouted insults at visiting Latortue and Alexandre.

The protesters included at least 20 rebels in blue T-shirts whose uprising began a rebellion that culminated in Aristide's February 29 ouster.

"If the government doesn't take responsibility for things here, then we will. Remember, it was Gonaives that got rid of Aristide," rebel Wilfort Ferdinand told protesters and hundreds of onlookers.

An estimated 200,000 people are homeless in Gonaives, many living on sidewalks and rooftops. Beating on buckets and waving tree boughs, protesters snaked through the crowd chanting, "We are not afraid and we won't give in to pressure!"

"The floods took everything we own. The government hasn't done anything. We don't want Latortue anymore," said Estime Derival, a 21-year-old protester.

The storm unleashed floods and mudslides that killed at least 1,870 and left some 884 missing, most presumed dead. Victims' relatives wailed and wept in the ceremonial funeral.

In Port-au-Prince, at least 26 people have been killed in violence that erupted as Aristide supporters stepped up protests September 30, demanding their leader's return from exile in South Africa and an end to "the invasion" -- referring to U.S. Marines who arrived as Aristide left and U.N. peacekeepers who took over in June.

Saturday's protest in Gonaives involved a different camp -- Aristide opponents. It was a striking shift because the heckling by some rebels came in the same square where Latortue praised them as "freedom fighters" after Aristide left.

More than 500 worshippers filled the St. Charles Boromee Cathedral as a choir sang hymns. The crowd outside swelled to about 2,000 as Latortue and Alexandre walked out escorted by police to the nearby mayor's office.

Latortue has blamed Aristide supporters for the violence in Port-au-Prince, saying they are behind a campaign called "Operation Baghdad" and the recent beheadings of three police and others.

Aristide supporters blame the violence on police and anti-Aristide gunmen, and criticize Latortue for not disarming rebels -- who include some ex-soldiers pushing to reconstitute the army that Aristide disbanded in 1995, four years after it ousted him in a coup.

The U.S. State Department warned Americans on Friday not to travel to the Caribbean country except for emergencies, citing "serious risks."

Police now have seven people jailed on suspicion of masterminding recent violence, including the pro-Aristide Senate president, an ex-legislator, a former police chief, and four other Aristide supporters, police spokeswoman Jesse Coicou said.

Copyright 2004 The Associated Press.