KOHAT, Pakistan (Reuters) -- A suicide car-bomber attacked a Pakistani military convoy, killing at least 20 people, police have said.
Militant violence and the spread of Pakistani Taliban are raising fears about prospects for nuclear-armed Pakistan, a vital U.S. ally in its to efforts to stabilize Afghanistan.
"The bomber was driving a pick-up truck which he rammed into a convoy passing by a security checkpost," said senior police officer Fareed Khan in the northwestern town of Kohat.
"At the moment, I can say at least 20 people, including soldiers and policemen, were killed," he said.
About eight vehicles in the convoy were destroyed in the attack near Kohat, 190 kilometers west of Islamabad, he said. Fifteen policemen and soldiers were wounded.
President Asif Ali Zardari told allies and aid donors in Tokyo on April 17 he would step up the fight against militants, adding that defeat for Pakistan would be defeat for the world.
Donors including the United States, Japan, Europe, Saudi Arabia, and Iran pledged more than $5 billion in fresh aid over two years at the Tokyo conference.
The pledges, bigger than an expected $4 billion, reflect worries that an economic meltdown in Pakistan, propped up with a $7.6 billion loan from the International Monetary Fund over two years, would benefit Al-Qaeda and other militant groups.
The government has struggled to come up with an effective strategy to deal with militancy, alternating in different areas between military offensives and peace deals.
But the militants have only gained strength.
Zardari, under pressure from conservatives, signed a regulation
on April 13 imposing Islamic Shari'a law in the Swat Valley to end Taliban violence there.
The strategy of appeasement has alarmed U.S. officials, while critics say the government has demonstrated a lack of capacity and will to fight the Taliban and Al-Qaeda.