PESHAWAR, Pakistan (Reuters) -- Pakistani aircraft bombed militants in the South Waziristan region on the Afghan border as government forces prepare for a ground offensive against the militant hub, security officials said.
The government says most attacks in the country -- including four big ones over the past week that killed more than 100 people -- are plotted in South Waziristan, the main bastion of Al-Qaeda-linked Pakistani Taliban and their allies.
"There's been a heavy bombardment. They targeted some militant hideouts as well as pro-Taliban tribal elders," said an intelligence agency official in the region, who declined to be identified.
Two ethnic Pashtun tribal elders were said to have been killed, he said.
Later, militants attacked a nearby military camp in the North Waziristan region, triggering a clash, residents and intelligence officials said.
Militant attacks have intensified as the army prepares to launch a ground offensive, with 41 people killed in a suicide bomb attack on October 12 after a brazen weekend raid on the army's headquarters in Rawalpindi.
A ground offensive in South Waziristan could be the army's toughest test since the militants turned on the state.
The army has not said when it would begin but Interior Minister Rehman Malik said at the weekend it was "imminent."
Air, Artillery Strikes
The military has been conducting air and artillery strikes for months, while deploying troops, blockading the region and trying to win over factions among various groups.
About 28,000 troops have been put in place to take on an estimated 10,000 hardcore Taliban, army officials said earlier.
Pakistani Taliban fighters made advances towards Islamabad early this year, raising fears about the stability of the nuclear-armed U.S. ally.
But government forces have made gains against the militants in recent months, largely driving them out of the Swat Valley, northwest of the capital, and their leader, Baitullah Mehsud, was killed by a missile fired by a U.S. drone aircraft in August.
But the militants are hitting back.
The October 12 blast in Shangla district, just to the east of Swat, the fourth big attack in a week, triggered selling on Pakistan's main stock market, which fell 1.3 percent.
The benchmark index was little changed on October 13, with dealers saying investors remained cautious.
"Due to the attacks over the past few days, foreign investors have slowed their activity which has resulted in a slowdown in local activity as well," said Sajjad Mankani, associate director at BMA Capital Ltd.
The army said Pakistani Taliban commander Wali-ur-Rehman was behind the October 10 attack on its headquarters in Rawalpindi, near Islamabad.
Commandos stormed an office building near the headquarters and rescued 39 people taken hostage by gunmen after an attack at a main gate of the headquarters.
Nine militants, three hostages and 11 soldiers were killed.