Drug hit men shot dead six Mexican policemen on patrol in the marijuana-producing state of Sinaloa, the latest in a growing stream of attacks on police, the local Attorney General's Office said Friday.

  A group of armed men blocked a busy road in Sinaloa's state capital, Culiacan, Thursday night and shot at the police with automatic weapons from two vehicles, a spokesman for the state attorney general said.

  “We believe the killers were drug hit men. The police were from different local and state units traveling together in the same vehicle,” he said.

  The attack came hours after a lone gunman in Mexico City burst in on a regional police chief who headed operations against trafficking and contraband as he was having lunch at a restaurant on a busy street, shooting him and a bodyguard to death.

  Two other bodyguards with the chief were seriously wounded.

  More than 560 police officers have been slain since President Felipe Calderón took office in December 2006 and launched a military crackdown on drug cartels, deploying about 25,000 army troops and federal police across the country.

Immigration officials fired:

  The Mexican government said Friday it has fired two officials who oversaw immigration offices on the Caribbean coast because they contradicted themselves under questioning in the case of 33 Cubans snatched from government custody.

  Interior Secretary Juan Camilo Mourino also said charges have been brought against “a significant number of immigration agents and officials,” but he did not specify how many or what those charges were.

  Mourino said the two officials – who oversaw immigration offices on the Caribbean coast, where undocumented Cuban immigrants increasingly land – were fired “because of the significant number of contradictions and inconsistencies” in their stories about the June 11 assault.

  “Whether the investigation results in charges against the regional director and assistant director, their behavior was far from correct, and that is why they were removed,” Mourino told reporters.

  The undocumented Cubans were taken by armed men from a bus carrying them to a government immigration detention center in southern Mexico.

  Some of the Cubans were later found in Texas.

Cartel extradition:

  Mexico agreed Tuesday to extradite a top leader of a Tijuana-based drug cartel to the United States, dismissing a judge's opinion that it would mean trying him on the same charges twice.

  The Attorney General's Office said Benjamin Arellano Félix could be sent to the United States for trial at any time. But his defense attorney, Americo Delgado, said he has 15 days to appeal the decision in federal court.

  Arellano was arrested in 2002 and has already been sentenced to 22 years in prison in Mexico on drug-trafficking and organized-crime charges. He also was sentenced to more than five years for weapons possession.

  Arellano was tried in Mexico for crimes committed before 1997, the office said.

  In the United States, he is wanted for trafficking that occurred in years afterward.

  He is also wanted for money laundering, for which he never was tried in Mexico.