At least four people were shot dead in the Mexican resort of Acapulco on Sunday.
According to official figures for the first half of 2017, the city's murder rate is second only to that of Tijuana.
Despite the high levels of violence, Acapulco tourism officials say the port is seeing "a major renaissance in its cruise ship arrivals" with 32 cruise ships expected to call this year.
The latest murders were due to fights between rival gangs, officials say.
Public security officials said that between January and June of this year, 714 people had been murdered in Tijuana and 412 in Acapulco.
Tijuana, on the Mexico-US border, has long had a reputation for being extremely violent as drug dealers and human traffickers ply their trade but Acapulco too has seen a rise in violence.
Mexican daily Milenio recently reported that between 1,800 and 2,000 businesses closed in the resort over the past three years due to high levels of extortion and violence.
Despite this, tourism bosses say Acapulco's beaches, nature, nightlife and cliff divers continue to be a major draw.
There has been a nationwide rise in murders in Mexico, with government data suggesting that 2,234 people were killed in June 2017 - the deadliest month in Mexico in at least 20 years.
Security experts say that the rise is caused by the fight for territory between rival criminal cartels after the extradition to the US of the powerful former leader of the Sinaloa cartel, Joaquin "El Chapo" Guzmán.