Two missiles were fired on Sunday at a military check-post in a remote tribal region in Pakistan where forces are hunting Osama bin Laden, but caused no casualties, officials said.
The attack on the check-post in a village near Wana, capital of the South Waziristan tribal region, came a day after the death of 11 people in what the military called a shootout between the troops and suspected Islamic militants.
The troops opened fire on Saturday on a van they thought to be carrying militants after a military base in the region, close to the Afghan border, came under mortar attack.
An intelligence official said those killed may not have been militants and the incident was the result of "mistaken fire". The military later said in a statement that some of those killed may have been "terrorists".
Mohammad Azam Khan, top administrative official in South Waziristan, told Reuters that two missiles were fired at a military check-post in the village of Shulam on Sunday morning.
"There were no casualties or damage. But we have asked the local tribe to identify and surrender those involved in the incident," he said after a meeting with tribal elders.
Khan said authorities had freed 16 men arrested after Saturday's incident. The official APP news agency reported that the government had formed a "high-powered committee" to probe the 11 deaths, but gave no further details.
TRIBESMEN ANGERED: Residents say tribesmen have been angered by the death of the van passengers - five locals and six Afghans among them.
Analysts say civilian killings will not make the task easier for Pakistani forces hunting al Qaeda militants and their mainly Pashtun Taleban allies who enjoy general sympathy among the Pakistani Pashtun tribes.
Islamic militants thought to be hiding in the border region include bin Laden, the world's most wanted man, blamed for the September 11 attacks on the United States in 2001.
But US and Pakistani officials on Saturday denied an Iranian state radio report quoting "an informed source" as saying bin Laden had been captured in the border region.
Pakistani troops this week arrested 20 suspects in an operation against al Qaeda and Taleban militants in South Waziristan. Officials said none were leading al Qaeda militants.
But US military officials in Afghanistan have spoken of a renewed urgency in hunting down key terror figures, including bin Laden, and have previously expressed confidence that the world's most wanted man would be captured this year.
They have said that US-led troops in Afghanistan and Pakistani troops were moving toward co-ordinated operations "A hammer and anvil approach" to prevent fleeing al Qaeda fighters escaping across the border.