Eight people were killed when a gang burned down a bar in the resort city of Cancun early on Tuesday.
At least 10 armed men attacked the Castillo del Mar, a nightclub outside the city's main tourist area, threatening patrons and then lighting the building on fire, NBC News reported.
The blaze spread quickly, overwhelming six women who worked in the establishment and two male customers, according to El Diario.
On Aug. 4, a man was detained nearby after allegedly trying to extort 40,000 pesos (over $3,000) from the bar in exchange for protection, El Diario reported.
Hector Alejandro Arellano, 36, who was managing the bar, escaped with some of the patrons, Mexico's Excelsior newspaper reported.
Quintana Roo state Attorney General Francisco Alor said the cause of the blaze is still under investigation.
"According to unofficial information, which we have not corroborated, two vehicles pulled up ... both black, and apparently six armed men tossed Molotov cocktails," Alor told a local radio station.
The bar offered table-dances and other entertainment, and had a rough reputation. Alor said the bar had had problems in the past, but did not offer any details.
Businesses throughout Mexico are often hit up for protection money by drug cartels, which sometimes set fire to those that refuse to pay.
Cancun has largely avoided the bloodshed in which more 28,000 people have died in drug-related violence since late 2006. However, drug cartels and immigrant traffickers operate in the area.
Cartels expandingWorsening violence has gripped Mexico over the past few years, as cartels battle each other for dominance and the government struggles to stem the trade of drugs north into the United States and weapons south into Mexico.
As the cartels gained power in recent years, they have expanded into different businesses, such as extortion and kidnapping.
Corruption among police officers, who are often poorly paid and badly equipped, compounds the problem. On Monday, the country's federal police said it had fired nearly 10 percent of its force this year for failing checks designed to detect possible corruption, a major obstacle in the country's battle against the drug gangs.
Federal Police Commissioner Facundo Rosas said that 3,200 officers have been dismissed this year for failing to meet the agency's standards.
Drug violence has surged since President Felipe Calderon intensified the crackdown on traffickers upon taking office in late 2006, claiming more than 28,000 lives.
In recent violence, a 12-hour battle between troops and gunmen left killed seven people in the eastern town of Panuco.
The gunmen opened fire and launched grenades at a government electricity station as they tried to escape the soldiers, causing a power outage in a large part of town, said Salvador Mikel Rivera, attorney general in the Gulf coast state of Veracruz, where Panuco is located.