Mexico's powerful interior minister, head of the government's bloody battle against drug gangs, died along with at least eight others in a plane crash on Nov. 4 during evening rush hour in central Mexico City.

Juan Camilo Mourino, 37, had been travelling in a small plane that crashed near the capital's main avenue, setting dozens of cars on fire.

The cause of the crash was unknown, but the pilot had reported a breakdown to the air traffic control at Mexico City airport moments before losing contact.

Mourino had led a government campaign against mounting drug-related violence - in which some 4,000 have died so far this year - including the deployment of some 36,000 troops across the country.

Security adviser Jose Luis Santiago Vasconcelos also died in the crash, in a massive blow to the government's anti-drug strategy.

"Nine died in the Interior Ministry plane," said Mexico City mayor Marcelo Ebrard later on Nov. 4, updating a previous toll of eight, including three crew.

"Forty were injured, including 20 hospitalized with different burns or injuries. Seven have serious burns because when the plane crashed there was a fire," Ebrard said on Televisa news.

The Interior Ministry Learjet crashed at 6:40 pm (00:40GMT) on a pedestrian street near the capital's main Reforma avenue.

"The explosion was enormous, the flames rose higher than the buildings on Reforma," a witness told AFP.

"It was horrible. I saw an enormous column of black smoke and I heard three explosions," said another witness, Nelly Cabrera.

Security forces evacuated the accident site shortly after the crash.

The plane had taken off from the central state of San Luis Potosi where Mourino had earlier signed a security accord.

President Felipe Calderon paid homage to "one of my closest collaborators and one of my best and closest friends," in a brief statement to journalists.

The government "will carry out all necessary investigations to find out the causes of the tragedy," Calderon said.

Mourino, who became interior minister in January, was a key figure in Calderon's cabinet.

Calderon said he was a politician who had "tact and the strategic capacity for dialogue to carry out reforms."

Mourino had been accused of favouring his family's businesses in contracts with state oil company Pemex when he was adviser to the Energy Ministry in 2003.