PESHAWAR, Pakistan (Reuters) -- Pakistani militants in a northwestern region have scrapped a peace deal with the government and vowed to launch attacks, threatening to open a new front against the army already fighting in two areas.
The military says it is nearing the end of an offensive in the Swat region, northwest of Islamabad, and is set to launch an assault on Taliban chief Baitullah Mehsud in South Waziristan on the Afghan border.
The offensive in Swat was launched two months ago after Taliban fighters thrust toward the capital, raising alarm both at home and among allies who need nuclear-armed Pakistan's help to fight Al-Qaeda and to tackle Afghanistan's insurgency.
A militant faction allied with Mehsud in North Waziristan, another militant hotspot also on the Afghan border, said it was ending a pact with the government because of U.S. drone-aircraft attacks and the presence of government forces in their area.
"Our leadership has decided that as long as U.S. drone attacks continue and security forces stay here, there will be no peace agreement," faction spokesman Ahmedullah Ahmedi said by telephone from an undisclosed location.
The United States has launched more than 40 attacks by pilotless drones in northwest Pakistan since the beginning of last year, many in North Waziristan.
Pakistan officially objects to the attacks, saying they drive the population into the arms of the militants. U.S. officials say the strikes are carried out under an agreement that allows Pakistani leaders to decry them in public.
Meanwhile, the government has said Mehsud and his followers in South Waziristan will be attacked next and defeated.
Mehsud carries a U.S. reward of $5 million and a Pakistani reward of 50 million rupees ($615,000). Analysts say Mehsud has become increasingly close to Al-Qaeda and the military says he is behind 90 percent of "terrorist activity" in the country.
Mehsud was accused of the December 2007 assassination of former Prime Minister Benazir Bhutto.
Security forces have been closing in on his headquarters, using aircraft and artillery to attack his positions while soldiers secure main roads.
The military shelled Mehsud's positions again on the evening of June 29 and a stray shell hit the wall of the home of a Reuters reporter on the outskirts of the region's main town of Wana. No one was hurt.
"There was heavy shelling for several hours and one shell hit my house. Thank God, everybody is safe," the reporter said.
North Waziristan has been relatively peaceful but Ahmedi, spokesman for the faction led by commander Gul Bahadur, said his men would go on the offensive.
"All commanders have been ordered to carry out attacks on security forces wherever they find them," Ahmedi said.
He also claimed responsibility for a Sunday ambush on a military convoy in which 16 soldiers were killed. It was the heaviest military toll in an attack in many months.
A military spokesman said 10 militants were killed after the ambush and the military would respond.
He did not say how but analysts say the army will be reluctant to open a new front as it focuses on Mehsud in South Waziristan and secures Swat. Many soldiers remain on the eastern border with old rival India.
With no Taliban leaders in Swat killed, concern has been raised about their ability to strike back. A Swat Taliban spokesman said this week his leaders were determined to fight on.
Nearly 2 million people have fled from fighting in Swat and other parts of the northwest since late last year and aid groups are struggling to raise funds to help them.
The government has said the displaced could start going home in days. But aid workers say many of the displaced from Swat are worried about security and reluctant to go home, fearing the Taliban will make a comeback.