Militants gunned down a provincial counterterrorism chief in eastern Afghanistan after ambushing his convoy, an official said Sunday.

Fayez Khan, who headed counterterrorism operations for Khost province, was driving home Saturday evening in a convoy with police and bodyguards when he was ambushed, said Tahir Khan Sabari, the province's deputy governor. Khan was killed immediately, though a short gunbattle ensued as the security forces battled the attackers, Sabari said.

Sabari said he believed the attackers were Taliban fighters because Khan's job made him an obvious target and because Khan was not known to have any personal feuds that would account for the attack.

One of the attackers was also killed and another wounded, Sabari said. There were no other injuries.

Government officials are common targets of the Taliban and other militant groups working to undermine the Kabul-based government. Attacks stepped up this month around the country's Aug. 20 presidential election, with the Taliban threatening voters and attacking polling stations.

Final results from the vote are still weeks away, but partial results from 35 percent of polling stations show President Hamid Karzai widening his lead over main challenger Abdullah Abdullah, a former foreign minister. Karzai needs more than 50 percent of the vote to avoid a runoff.

Hundreds of major fraud allegations have to be investigated before any official results are released.