Pakistani forces on Friday stepped up an offensive they believe has cornered and perhaps wounded Osama bin Laden (news - web sites)'s deputy Ayman al-Zawahri, using artillery and helicopter gunships to attack militants near the rugged Afghan border. Fighting spread Friday to two more villages in South Waziristan, where hundreds of paramilitary forces began an operation against al-Qaida and Taliban fugitives four days ago. Townspeople said heavy guns fired through the night and they saw jet fighters in the area, although it wasn't clear if the aircraft had opened fire. Pakistani President Gen. Pervez Musharraf said a "high value" target was believed trapped, and three senior Pakistani officials told The !@#$%^&*ociated Press late Thursday that intelligence indicated it was al-Zawahri. Pakistani forces battled with hundreds of militants in five villages near South Waziristan's main town of Wana, pounding fortress-like mud-brick compounds as entrenched suspects fought back. An intelligence official said "dozens" were killed Thursday, and some of their hide-outs had been flattened. At least 41 people — 15 soldiers and 26 suspected militants — were killed earlier this week in fighting in the area. This semiautonomous tribal region, which has resisted outside control for centuries, has long been considered a likely hiding place for the top two al-Qaida leaders — but there was no indication bin Laden was with the Egyptian-born al-Zawahri. However, the two have traveled together in the past, and bin Laden and al-Zawahri appeared jointly in video tapes released shortly after the Sept. 11, 2001, attacks on the United States. The United States has offered a $25 million reward for information leading to al-Zawahri's capture. On Thursday, the U.S. House of Representatives doubled the reward for bin Laden's capture to $50 million. "We have been receiving intelligence and information from our agents who are working in the tribal areas that al-Zawahri could be among the people hiding there," a Pakistani military official said. "All of our efforts are to capture him." An intelligence official and a senior politician in Musharraf's government both confirmed the account. All spoke on condition of anonymity. The intelligence official said information also was coming from some of the 18 suspects captured Thursday. Some said during interrogation that al-Zawahri was wounded in the raid, the official said. Musharraf told CNN that he'd spoken with the commander of Pakistani troops in the region. He said the commander reported "fierce resistance" from a group of fighters entrenched in fortress-like buildings. "They are very strong there. They are dug in," he said. "It's a pitched battle." The president added that there were indications a senior figure was surrounded, but he didn't provide a name. "He's reasonably sure there's a high-value target there," Musharraf said. "They are not coming out in spite of the fact that we pounded them with artillery." Information Minister Sheikh Rashid Ahmed said Friday the siege was "narrowing down," and it would only be possible to identify that target when troops get closer. "They (the militants) are giving a tough contest. They have built bunkers in their homes," he told AP. U.S. National security adviser Condoleezza Rice (news - web sites) told CNN that if al-Zawahri were captured, it would be "a major step forward in the war on terrorism," although it wouldn't mean the break up of al-Qaida. Deputy Defense Secretary Paul Wolfowitz, speaking on PBS' News Hour With Jim Lehrer, said that "anyone who thinks that that's (the capture) going to be the ... end of these terrorists networks, doesn't understand how they work." He called them decentralized groups that must be hunted down "one by one." Gen. Richard Myers, chairman of the Joint Chiefs of Staff, also told CNN that terror attack were likely to continue after any capture. "It won't end the terror." The 52-year-old former Egyptian surgeon is believed to be the brains behind the terror network, with bin Laden serving more as spiritual leader and financial backer. He is also thought to have served as al-Qaida leader's personal physician. He has often been seen by bin Laden's side in videos released to Arab television networks. In a broadcast on Feb. 24, Al-Zawahri taunted President Bush (news - web sites) and threatened more attacks on the United States. Under pressure from Washington, Pakistan has arrested more than 500 al-Qaida suspects and has turned most over to the United States. The last major capture was that of Khalid Shaikh Mohammed, the former al-Qaida No. 3, who was nabbed on March 1, 2003, near the capital and quickly delivered to U.S. custody. He is being held at an undisclosed location. On Thursday Secretary of State Colin Powell (news - web sites) announced in the capital, Islamabad, that Washington was bestowing the status of "major non-NATO (news - web sites) ally" on Pakistan, and praised the country for its help in the war on terror. Brig. Mahmood Shah, the chief of security in Pakistan's tribal areas told AP that the current operation was extended to other villages near Wana. Residents reported artillery s-*BAD WORD*-s landing Friday in Zera Letha and Ghawa Khawa villages, while at least two helicopter gunships fired small arms and Pakistani jet fighters flew overhead. Shah estimated that between 300 and 500 al-Qaida fugitives and supporters were in the area. He said the suspects were using light and heavy weapons and could not forecast how long the operation would last. "Our effort is to take this operation to its logical end," he said. "It may take some time." Security officials in Wana said a stray mortar hit a village home Thursday, killing a boy and wounding seven of his relatives. It wasn't clear which side fired it. An AP reporter and photographer on Friday were blocked by authorities at a roadblock about one hour's drive from Wana and prevented from going farther. U.S. officials say they are watching to see if the Pakistani actions send militants back into Afghanistan (news - web sites), where U.S. troops operate freely. A senior Afghan Defense Ministry official said Afghan and U.S. troops tightened three days ago their cordon along the frontier, including around the U.S. base at Shkin, about 15 miles from Wana. Some 250 extra Afghan troops left Kabul Thursday for the border province of Khost, just to the north, Gen. Atiqullah Ludin said. "Al-Qaida cannot escape or enter Afghan soil," he said.