Mexican marines have detained nine drug cartel suspects and seized an arsenal that included an anti-personnel mine and grenade launchers after gunfights that killed a police officer, authorities said Thursday.

The troops also confiscated 24 assault rifles when they arrested the suspects late Wednesday in the northern state of Tamaulipas, a regional security task force said in a statement.

The suspects are accused of participating in an assault by the Gulf cartel earlier on Wednesday in Altamira, near the Gulf of Mexico coast.

Authorities say the gang opened fire in the town and blocked roads with burning vehicles in an attempt to rescue a leader who had just been arrested by authorities.

One police officer was killed and two were wounded. Officials had previously reported no fatalities.

The mayhem in Altamira came just five days after a similar bout of violence in Reynosa, a city bordering Texas.

Last Friday, dozens of Gulf gunmen tried to rescue a captured drug lord in a day of violence that left three suspects dead in the border city.

The Gulf cartel has been weakened and mired in internal power struggles following the arrests of several leaders in recent years.