ACAPULCO, Mexico -- Gunmen launched grenades and opened fire in near simultaneous attacks on two police stations in Acapulco Monday, killing three officers in violence that broke out less than 48 hours after a gunbattle in the resort left 17 dead.

The bold, pre-dawn attacks Monday also wounded one police officer in this Pacific resort city, which has long been plagued by drug violence.

Gunmen fatally shot two officers sitting in a patrol car parked outside one police station. A few minutes later, assailants attacked a second station, about two miles (three kilometers) away, wounding two officers, according to the Guerrero state police department. One of the officers later died.

A state police official, who was not authorized to give his name, said investigators are looking at whether the attacks were in retaliation for late Saturday's gunbattle.

The weekend shootout between soldiers and alleged drug traffickers killed 13 suspected hit men, two soldiers, and two innocent bystanders, Daniel Velasco, a military commander in Acapulco, told reporters Monday. One bystander was wounded. The Defense Department in initial reports mistakenly said 18 people had died.

A hit man named "Commander Magana" with the Beltran Leyva cartel was among the dead, Velasco said.

Thousands of shots and 50 grenade explosions marked the battle, which erupted after soldiers received a tip that a group of armed men were gathered at a gated house less than 100 yards (meters) from the Los Flamingos Hotel that was once a private club for Hollywood stars including John Wayne and "Tarzan" star Johnny Weissmuller.

Several gunmen tried to flee but crashed their car into a military Hummer that was blocking the gate. At one point, more armed men with grenades arrived to reinforce the men in the house, but they died in the shooting, said an army colonel, who led the operation and spoke on condition of anonymity for security reasons.

Inside, soldiers found four men bound and shirtless who claimed they were Guerrero state police officers being held hostage. The alleged officers and one other person inside the house were detained, the Defense Department said in a statement.

Soldiers did not know the hostages were inside when the shootout began, and the colonel said the four men's claims to be police would be investigated.

The soldiers confiscated 47 guns, grenades and ammunition, as well as several cars, including a Mercedes Benz.

Guerrero state, where Acapulco is located, has long suffered from drug violence from cartels fighting for turf.

The Beltran Leyva cartel, in particular, has a strong presence in the state. Last month, soldiers arrested a suspected cartel lieutenant as he stepped off a private plane in the northern city of Monterrey on his way back from Acapulco, where he said he'd met with cartel leader Arturo Beltran Leyva at a baptism party.

President Felipe Calderon has sent at least 3,000 soldiers to Guerrero state as part of his nationwide crackdown on organized crime launched in 2006. Since then, more than 10,800 people have been killed by drug violence nationwide.