A suicide bomber blew himself up at a police checkpoint Saturday in a volatile area of eastern Afghanistan, killing 13 people, police said.
The bomber walked up to a checkpoint in Ali Sher district along the Pakistan border in Khost province and detonated his explosives-rigged vest, said provincial police chief Gen. Sardar Mohammad Zazia. The policemen were searching motorists' vehicles at the time of the explosion, he said.
"The aim of the attacker was to attack both police and civilians," he said. "Unfortunately, the majority of the victims are civilian."
In a statement, the governor's office in Khost province said 13 people died in the blast _ 10 civilians, two Afghan policemen and one Afghan border police officer. Six other people were wounded, including two border policemen, the governor's office said.
Heads of state were gathering for a NATO summit in Chicago to discuss the security needs of Afghanistan after most foreign troops leave or move to support roles by the end of 2014.
In the past two years, tens of thousands of U.S.-led coalition troops have flooded Taliban strongholds in the south, and have largely succeeded in boosting security there. But the Taliban have proven resilient, opening up new fronts in the north and west and stepping up attacks in the east.
The Afghan government and U.S. have had informal discussions with members of the Taliban interested in talking peace, but none of the discussions have reached the stage of formal peace talks. The last substantive discussions between U.S. officials and Taliban representatives were in January.
Earlier this month, militants assassinated Arsala Rahmani, a top member of the Afghan government-appointed peace council, dealing another setback to the fragile peace effort. The Taliban denied responsibility for the killing.
In September, former President Burhanuddin Rabbani, the head of the peace council, was killed at his home in Kabul by a suicide bomber who claimed to be peace emissary from the Taliban.
Afghan President Hamid Karzai was asked Saturday in Chicago ahead of the NATO summit whether he still had hope that his government could reconcile with the Taliban.
"Those Taliban who are not against Afghans, we welcome them," he told German television stations ZDF and RTL, according to a statement released by his office in Kabul. "Those Taliban who are committing crimes _ like burning our schools, setting bombs, killing children and innocent people _ they should stand in front of the Afghan people and ask for forgiveness and then join with the peace and reconciliation process."