Peshawar, Pakistan ? More than 3,000 soldiers searched mountains, houses and vehicles near the Afghan border Saturday as the army stepped up its hunt for suspected al-Qaida fugitives in the remote tribal region, officials said Saturday.

The troops, backed by helicopters and FBI intelligence, have arrested at least 20 men since Wednesday in the largest Pakistani deployment against al-Qaida infiltration since September, when President Gen. Pervez Musharraf pledged support for the U.S.-led war on terrorism, authorities said.

Pakistani Interior Minister Moinuddin Haider said the U.S. government would give his army five modern helicopters and three surveillance airplanes next week to help monitor the volatile border region that operates largely outside of central government control, according to a Saturday report by the Islamabad newspaper Ausaf.

The house-to-house searches, mountain patrols and roadblock checks began after more than 40 suspected al-Qaida fighters on Wednesday killed ten Pakistani soldiers near the border town of Wana, about 190 miles west of Islamabad.

A Pakistani intelligence agent, speaking on condition of anonymity, said the 20 al-Qaida suspects arrested in the past four days included Chechens, Sudanese, Nigerians and Afghans accused of involvement in the border clash.

A Pakistani major and a captain were among those killed Wednesday and several soldiers were wounded. Two suspected al-Qaida fighters were killed and one, a 15-year-old boy, was captured. The rest of the fighters escaped in the dark.

Immediately after the attack, the government deployed 500 soldiers to help the 100 or so troops already in the North West Frontier Province to hunt the fugitives, suspected to have fled after the U.S. military’s Operation Anaconda in southeastern Afghanistan in March.

Nearly 2,500 more soldiers have since joined in the search in the region, which is inhabited by fiercely independent, conservative tribesman, many of whom support al-Qaida or the ousted Afghan Taliban regime.

Wana residents said the army also sent in civilian women to help with searches involving other women.

U.S. officials estimate that up to 1,000 al-Qaida fighters still operate in small groups on both sides of the mountainous border.

Wednesday’s battle broke out before dawn when soldiers approached a suspected al-Qaida hide-out near Wana. More than 40 men attacked them with rocket-propelled grenades, assault rifles and hand grenades, the army said.

The Pakistani military casualties were the first since the government deployed troops to the area that borders two Afghan provinces south of Kabul last year to intercept al-Qaida and Taliban members fleeing U.S. attacks.

Local government buildings and Pakistani troops have come under sporadic rocket and machine-gun fire from unknown attackers in the area in recent weeks.