Pakistani troops fought new battles with gunmen near the Afghan border as fears spread on Wednesday of a campaign of retaliation against the offensive aimed at rooting out al Qaeda members and their supporters.
A rocket attack on Peshawar injured three people, intensifying concerns of a backlash by tribal people furious at the offensive in the semi-autonomous region.
Thousands of Pakistani troops have been carrying out a major operation to kill or capture al Qaeda members and anyone sheltering them in the wild border areas since last Monday.
At the main focus of the fighting, tribal elders set up to 500 besieged fighters a new deadline to surrender.
The terrorists, positioned in two villages near Wana, the main town of South Waziristan, must give themselves up by 10:00 am (0500 GMT) on Thursday or face "serious consequences", the authorities warned.
The terrorists have been holding out against 7,500 Pakistani troops backed by helicopter gun-ships and artillery since last Thursday.
As well as the Peshawar rocket attack, four people died on Tuesday at a police post in Bannu, some 40km north-east of Wana.
It was unclear if the deaths were caused by an explosive device or friendly fire, security sources said.
"These incidents are most probably a backlash to the anti-terrorism military operation," a senior security official told AFP.
Officials said the two sides exchanged fire in the early hours of Wednesday as the operation entered its ninth day.
"There were occasional exchanges of fire in Shin Warzak area," Military Spokesman Major General Shaukat Sultan told AFP. Witnesses said firing could also be heard in the area later on Wednesday.
The religiously conservative tribes, sympathetic to the Taleban and al-Qaeda, are furious at civilian casualties and the destruction of private homes in the fighting and searches for terrorists.