Suspected Taliban militants ambushed a convoy of Afghan police officers driving through a dangerous section of the country's major highway Wednesday, killing six, an official said.

In other attacks, suicide bombers hit a police station in the east and a convoy in the capital, claiming at least three victims.

The ambush came along the Kabul-Kandahar highway, a ribbon of road that connects Afghanistan's two major cities. Long stretches of Highway 1 run through areas controlled by Taliban militants.

Six police were killed and five wounded in the ambush in the southern Zabul province, said Gen. Yaqoob Khan, the provincial police chief. Two vehicles in the convoy were damaged, he said.

Police are frequent targets of militant attacks, in part because the force has less training and is not as well equipped as the Afghan army.

In the east, insurgents attempted a double homicide bombing at Khost's provincial police station. One bomber blew himself up and killed at least three police. A second bomber who then ran into the police headquarters was shot and killed, said Mohammad Wali Shah, the provincial police chief.

In Kabul, a suicide bomber on foot targeted a convoy of Turkish vehicles on the capital's outskirts, injuring one Afghan civilian, a police official said.

The explosion hit a vehicle with diplomatic license plates, but it wasn't immediately known who was traveling inside the car. The blast slightly damaged the vehicle.

One Afghan was wounded in the attack, said Zalmay Khan, Kabul's deputy police chief. Only the suicide bomber was killed.

Violence has spiked in Afghanistan the last several weeks. More than 3,300 people have died in insurgency-related violence this year, according to an Associated Press count based on numbers from Afghan and Western officials.