ISLAMABAD, May 22 (Xinhua) -- At least four militants were killed by Pakistan's security forces in an operation to clear their training facility in the country's North Waziristan tribal region Tuesday, an army spokesman said.

    Large quantities of arms, ammunition and training material was also recovered from the suspected militants' training facility in Zargarkhel area of North Waziristan, said Waheed Arshad, Pakistan's military spokesman, quoted by state media.

    The security forces cordoned the area on receiving information and launched the operation early in the morning after the militants refused to surrender, according to the official.

    Members of a peace committee were flown in on a helicopter for negotiations, asking the militants to surrender. But the militants refused talks and opened fire on the security forces.

    Pakistan, joining Washington-led war on terror in the wake of Sept. 11 2001 attacks, has sent some 80,000 troops to hunt Talibanand al-Qaida members who sneaked into Pakistan to seek shelter following Afghan Taliban regime fall.

    The Pakistani government reached a peace deal with local tribesmen in North Waziristan in September 2006 to stop attacks on security forces inside Pakistan and expel foreign militants.