Pakistan - Pakistani aircraft bombed militants in the South Waziristan region on the Afghan border on Tuesday 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 major 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.

Pakistani Taliban fighters made advances toward 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.

Militant attacks have intensified as the army prepares to launch a ground offensive in South Waziristan, with 41 people killed in a suicide bomb attack on Monday after a brazen weekend raid on the tightly guarded army headquarters in Rawalpindi.

A Taliban spokesman who earlier claimed responsibility for the assault on the headquarters, said a Taliban bomber carried out Monday's attack to avenge the blood of our martyrs.

Wait for more, spokesman Azam Tariq said by telephone.

TOUGHEST TEST

The 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 has said it was imminent.

They are enemies of Islam and Pakistan. They're hired killers. Their sole target is to destabilize Pakistan, to bring misery to the people but we'll rout them, he told reporters.

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.
Monday's 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 edged up on Tuesday, but investors remained wary.

The army said Pakistani Taliban commander Wali-ur-Rehman was behind Saturday's attack on its headquarters in Rawalpindi, near Islamabad.

Commandos stormed an office building near the headquarters on Sunday 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.

The raid on the heart of the military establishment by militants disguised as soldiers followed a warning that just such an assault was being plotted.

That has led to accusation in the media of an intelligence failure but Malik defended the security agencies.

Stop hitting our intelligence agencies. Nobody works harder than they do. They foil 100 attacks which you don't notice but if one incident happens you all start criticizing them, he said.

(Additional reporting by Hafiz Wazir; Writing by Robert Birsel; Editing by Alex Richardson)

Pakistan