ACAPULCO, Mexico -- Eight people were killed and five other bodies found in a clandestine grave in Acapulco on a particularly bloody Sunday for the violence-plagued Pacific coast resort city.

"It was a horrible day," said Roberto Alvarez, security spokesman for Guerrero state, which is home to Acapulco.

The violence began early when police were alerted to the dead bodies of three young men found with tourniquets around their necks and signs of torture in the San Agustin neighbourhood on Acapulco's northern outskirts.

Later in the morning, a gun battle broke out between police and armed men on a central avenue, setting off a chase that ended with one suspect killed and three arrested.

Still before noon, two gunmen stormed into a bar and shot dead a man and a woman who were drinking there. Police patrolling nearby responded and caught the aggressors.

The suspects told police that the bar contained a clandestine grave, and an excavation by authorities turned up the bodies of four men and one woman. Authorities said they were resuming the search Monday on the belief that more bodies could be hidden on at least two adjacent properties.

On Sunday afternoon, gunmen killed two men two blocks from the same central avenue where the police chase had taken place earlier. Neighbors found the bodies and notified the police.

Guerrero state has been among Mexico's worst hotspots for drug gang violence in recent years. Guerrero recorded 1,726 homicides from January through September, according to federal statistics, up slightly from 1,654 during the same period last year and well more than any other state in the country.

Elsewhere in Guerrero, residents of the municipality of Copanatoyac reported four dead bodies had been found dumped in a gully Sunday. Alvarez, the state security spokesman, said officials were also working to confirm reports of murders in Iguala, Taxco and Tlapa.