| DERA ISMAIL KHAN, Pakistan
DERA ISMAIL KHAN, Pakistan Pakistani helicopter gunships attacked Taliban bases near the Afghan border on Wednesday as authorities ordered educational institutions closed amid fears of retaliatory militant strikes.
Pakistani forces launched an offensive to wrest control of the lawless South Waziristan region on Saturday after militants rocked the country with a string of bomb and suicide attacks, killing more than 150 people.
A day after six people were killed in two suicide bomb attacks at an Islamabad university, authorities ordered schools and colleges closed, unsettling stock investors, with the main index ending 3.36 percent lower at 9,247.78.
"The tense law and order situation as evidenced by the closure of schools throughout the country has truly spooked stock market investors," said Asad Iqbal, managing director at Ismail Iqbal Securities Ltd.
Remote and rugged South Waziristan, with its rocky mountains and patchy forests cut through by dry creeks and ravines, is a global hub for militants.
The offensive is being closely followed by the United States and other powers embroiled in Afghanistan.
Government forces initially faced light resistance, but fighting has intensified as soldiers approach the militants' main sanctuaries in the mountains.
Security forces attacked the militant strongholds of Makeen and Ladha with helicopter gunships and artillery on Wednesday, security officials said.
Qari Hussain Mehsud, a Taliban commander known as "the mentor of suicide bombers," called the BBC to take responsibility for Tuesday's attack on the International Islamic University in the capital and said all of Pakistan was a war zone.
The army reported intense fighting for the control of Kotkai, Hussain's hometown and also the birthplace of Pakistani Taliban chief Hakimullah Mehsud.
Security forces briefly took control of Kotkai in fighting on Monday but militants recaptured it in a counter-attack.
Separately, four militants, including two Arabs, were killed in neighbouring North Waziristan when a bomb they were making went off accidentally, security officials said.
NUCLEAR INFRASTRUCTURE IS SAFE
Pakistan's media and public generally back the offensive, but the alarm spread by the order to close schools, and the slide in stocks that that triggered, showed public disquiet.
An intensification of militant attacks in urban centres could begin to test the public's patience. The Waziristan offensive could take weeks, analysts say.
The News daily splashed the attack at the university across its front page with the headline "Godless kill in God's name."
Prime Minister Yusuf Raza Gilani chaired a cabinet meeting and vowed the government was "more resolute" to eradicate militancy.
He also assured the nation and the international community that Pakistan's nuclear infrastructure was safe and "these terrorists pose no threat to its safety."
As government forces pressed ahead with the offensive, the military called on the NATO troops in Afghanistan to seal the border "to prevent cross-border movement and flow of weapons."
Pakistani newspapers have in recent days reported that NATO forces had abandoned border posts opposite South Waziristan, raising the possibility of Afghan Taliban coming to help their Pakistani comrades, or of Pakistani Taliban fleeing.
Pakistan Joint Chiefs of Staff Committee Chairman General Tariq Majid called for "synchronisation of effort on both sides and sharing of real-time intelligence with reference to the ongoing operations," the army said in a statement.
The army says 115 militants and 16 soldiers have been killed since the offensive was launched, but there was no independent confirmation of those tolls.
Foreign reporters are not allowed near the battle zone and it is dangerous for Pakistani reporters to visit. Many of the Pakistani media based in South Waziristan have left.
About 28,000 soldiers are battling an estimated 10,000 hard-core Taliban, including about 1,000 tough Uzbek fighters and some Arab al Qaeda members.
More than 100,000 civilians have fled from South Waziristan, with about 32,000 of them leaving since October 13, the United Nations said. Up to 200,000 people could flee, the army says.
The army has launched brief offensives in South Waziristan before, the first in 2004 when it suffered heavy casualties before striking a peace pact.
(Additional reporting by Zeeshan Haider; Editing by Robert Birsel and Ron Popeski)