An Associated Press journalist saw the four bodies, including a man who lay on a central avenue in Acapulco in broad daylight Sunday with a pink towel over his face. Pedestrians watched from a footbridge as police secured the scene.

The deaths came as Mexico's violence reached new heights with 2,234 murders in June, the country's deadliest month in at least 20 years, according to government data. For the first six months of 2017, authorities nationwide recorded 12,155 homicide investigations, or 31 percent more than the 9,300 during the same period last year.