NEW DELHI -- In a high-profile attack, at least five militants entered an airbase in the northern Indian state of Punjab early Saturday, triggering a gunfight with security forces in the first major terrorist attack in India this year.

Security forces said at least two gunmen have been killed and the remaining attackers are holed up in a building at the airbase, while security forces are carrying out a combing operation against them.

Two air force personnel were also killed in the attack, said local newspaper Hindustan Times online.

The attack took place at the Pathankot airbase where Mig28 fighters and helicopters are based. The purpose of the attackers was to destroy the base, according to officials.

On Friday an alarm was sounded in the state over the assault of a top police officer by suspected terrorists. One policeman was killed and another kidnapped but later released, according to TV reports.

A group of 50 commandos of the National Security Guard (NSG) have been leading the fight against the militants in Pathankot since Saturday morning and TV footage showed heavy deployment of military trucks and at least one helicopter was searching for the remaining militants.

Reports said the militants might belong to a group called "Jaish-e-Mohammed," which is from Kashmir but is now operating from Pakistan. It is banned in Pakistan and listed as terrorist by India and some other countries.

The attack was reminiscent of the Gurdaspur strike last year when a number of militants crossed border from Pakistan and attacked the border town in Punjab.

In both times, the attackers were wearing army fatigues and came with civilian cars.

Pathankot has an army cantonment and an Air Force base kilometers away from the Pakistan border.

The Pathankot attack came soon after Indian Prime Minister Narendra Modi made a surprise visit to Lahore last month and held talks with his Pakistani counterpart, Nawaz Sharif.