Last weekend, the La Familia drug cartel launched a series of attacks against police posts in Michoacan that left four people dead, including three members of the security forces and one suspected cartel hitman.

The attacks were "desperate and violent reactions" to the government's crackdown against the cartels, Felipe Calderon, the Mexican president, said on Monday.

Michoacan - Calderon's home state - has also seen violent clashes between rival drug cartels.

Gang retaliation

Authorities said the cartel attacks came in retaliation for security agents having detained Arnoldo Rueda, the La Familia kingpin.

They say that Rueda, nicknamed La Minsa and allegedly La Familia's second in command, is an important cartel operative in charge of managing synthetic drug production and shipping marijuana and cocaine to the US, the world's biggest consumer of cocaine.

La Familia, which operates mainly in Michoacan, burst into the  headlines in October 2006 when an armed commando linked to the cartel entered a bar and tossed five severed heads onto the dance floor.

The government has deployed 36,000 soldiers and federal police to the cities most affected by drug violence.

More than 7,700 people have been killed in drug violence in Mexico since 2008, according to government figures.