Mexico City: Mexico's acting federal police chief was shot dead early Thursday outside his home - a brazen attack as drug traffickers increasingly lash back at a nationwide crackdown on organised crime.

Edgar Millan Gomez, 41, was shot ten times after opening the door to his Mexico City apartment complex, where at least one gunman was waiting for him before dawn, the Public Safety Department said. Two bodyguards were also wounded.

Millan died hours later at a hospital.

President Felipe Calderon's government said Millan had played a vital role in the country's fight against organised crime and denounced "this cowardly killing of an exemplary official".

Police were investigating and had not yet determined a motive for the pre-dawn attack. One suspect with a record of car theft was arrested.

Envoy's condolences

US Ambassador Tony Garza sent his condolences to Millan's family. "Mexico has lost another hero," Garza said in a statement.

"Another death which brings outrage to all who admire and respect the thousands of selfless officials who dedicate their lives to the betterment of their country."

Since taking office in 2006, President Calderon has sent more than 24,000 soldiers to drug hotspots. Millan was in charge of coordinating operations between the federal police and those troops.

Cartels have responded fiercely to the nationwide offensive, killing soldiers and federal police in unprecedented attacks.

Until recently, most of those killings took place in northern Mexico, where drug gangs rule large areas. Now, criminals appear to be getting more brash with slayings in the capital Mexico City.

George Grayson, a Mexico expert at the College of William & Mary in Virginia, said Millan's death "shows the increasing audacity of the cartels".