Gunmen on motorcycles ambushed and killed Honduras' top anti-drug official in the capital Tuesday, just two months before he planned to retire and move to Canada.

Former army Gen. Julian Aristides Gonzalez, director of the Office for Combatting Drug Trafficking, was driving alone after dropping his daughter at school when assailants opened fire and then fled, national police spokesman Orlin Cerrato said.

No arrests have been made, and investigators were trying to determine a motive. Last year, Gonzalez said he had received death threats from drug traffickers.

"We regret the death of this man who offered his life for the welfare of Hondurans," Cerrato said. "By the decency of his actions, he unleashed a real battle against the main vice that besets humanity."

Gonzalez, 57, served five years in the post and was preparing to step down in two months, when Honduras' new president takes office. He had planned to move to Canada, Cerrato said.

His wife is a major in the Honduran army.

Honduras is a key transit country for drug smuggling, which authorities say probably increased after the United States suspended anti-narcotics cooperation and development aid to protest the June 28 coup that ousted leftist President Manuel Zelaya.

Police said they have detected more aircraft carrying drugs from South America to Honduras since the coup, but have been hindered in stopping the planes without the help of U.S. helicopters and radar technology.

So far this year, Gonzalez's office has seized 5 tons of cocaine brought into the country by more than three dozen planes, most from Venezuela and Colombia.

The government estimates 100 tons of U.S.-bound cocaine passes through Honduras each year. Concerned about the increase in drug trafficking, Gonzalez held a press conference Monday in which he urged the public to help him by reporting any suspicious activity.

Also Tuesday, gunmen killed retired Col. Osiris O'Connor, 54, and his driver in the town of El Eden, about 60 miles north of Tegucigalpa, police spokesman Nazir Lopez said.

Lopez said police do not believe his death was related to the attack on the drug chief. He had no further details.

Honduras has one of the highest crime rates in Central America.