"The suicide attack happened at about 10 a.m. this morning in Bande Sardeh area. The suicide attacker carried the bomb in his bicycle, and collided one Turkish engineer car. Both the driver and the attacker were killed, and two Turkish engineers in the car were injured," said the official on condition of anonymity.
The highway police chief of the area Abdul Razaq confirmed the attack and the death toll, but he said only one Turkish engineer in the car was injured.
"We have blocked the highway for a few hours after the attack, and the investigation is still going on," Razaq added.
Remnants of the former Taliban regime have stepped up another surge of violence against Afghan government and foreign troops from spring, with the aim of destroying stability of the country and the upcoming September parliamentary election. At the same time, Afghan forces also intensified their attacks against Taliban militants.
Afghan National Police (ANP), backed by the US-led coalition troops, have killed five suspected Taliban militants and detained nine others in southern Zabul province since Saturday, a spokesman of the Interior Ministry said Sunday.
Six Afghan troops were killed and a police chief and his driver wounded Saturday when their convoy hit a roadside bomb in Afghan eastern province of Paktika.
On Thursday, Taliban also killed three elders who were thought by Taliban to work for the United States, but denied by the Afghan government.
Afghan and US troops killed one Taliban militant Thursday, and killed two more on Saturday when they were patrolling in Afghan southern province of Kandahar, US military said Saturday.
In a fight on Friday night, Afghan forces killed 30 Taliban militants in Afghan southern province of Uruzgan, provincial governor said on Saturday.