An army shell intended for a militant hide-out accidentally killed six civilians in northwestern Pakistan on Wednesday, police said.
Dozens of people dragged the bodies onto the main highway running through North West Frontier Province, blocking traffic to protest the killings.
The demonstrators chanted "stop the killing of innocent people" and "stop this cruelty," said Hashim Khan, a local resident who participated. The protest lasted about two hours and then dispersed peacefully, he said.
The dead included three women, two children and a man, said a local police official, speaking on condition of anonymity because he was not authorized to talk to the media. The accident occurred in Shahukhel, a town in the Hangu district of the province, he said.
Hangu is close to two areas in Pakistan's semiautonomous tribal region where jet fighters also pounded militant hide-outs Wednesday killing 18 suspected fighters, said intelligence and political officials.
The attacks come as the Pakistani army is waging a major offensive in the South Waziristan tribal area near the Afghan border, where al-Qaida and Taliban leaders are believed to be hiding.
Officials believe many militants have fled South Waziristan, seeking refuge in other parts of the tribal region and elsewhere in Pakistan.
Jet fighters pounded two hide-outs used by militants loyal to Pakistani Taliban leader Hakimullah Mehsud in the Orakzai tribal area, killing 13 suspected fighters, said the officials.
Planes also attacked compounds in the Kurram tribal area, killing five militants who had fled South Waziristan, said the officials, speaking on condition of anonymity because they were not authorized to talk to the media.
Pakistan's army has pitted some 30,000 troops against up to 8,000 militants in South Waziristan, including many Uzbeks and other foreign insurgents who have long taken refuge in the lawless tribal areas.
Commanders say Pakistani troops have retaken most population centers, roads and strategic high ground in the region but that insurgents remain in parts of the countryside.
The most recent fighting in South Waziristan killed six militants and injured eight soldiers, the army said in a statement Wednesday.
The information is impossible to verify independently since Pakistan has blocked access to the battle zone.
Associated Press writer Riaz Khan contributed to this report from Peshawar.