A brutal gang rape and other crimes have prompted a massive security operation for Acapulco's tennis tournament, with 4,000 personnel to be deployed at an event headlined by Rafael Nadal.

The Pacific port has become Mexico's deadliest city and local police have struggled to stem a brutal turf war between drug gangs where the intimidation of rivals includes the dumping of headless bodies in the street.

The unprecedented show of security at the tennis event is three times the size of Acapulco's own police force and will feature army, navy, federal, state and municipal police, a senior Guerrero state government official said.