Suspected militants fired at a bus station and entered police barracks on the outskirts of a northern town bordering Pakistan early Monday, wounding at least six people, police said.

Senior police officer Dinkar Gupta said the attackers were believed to have come from the Indian portion of Kashmir.

They hijacked a car and then fired at a bus station and entered a nearby police station near Gurdaspur, a border town in Punjab state, Gupta said.

Police reinforcements have reached the area and were engaged in an exchange of gunfire with the rebels holed up in the barracks, he said.

New Delhi Television news channel said three to four rebels carried out the attack.

Gurdaspur is 450 kilometers (280 miles) north of New Delhi.

Rebels have been fighting for an independent Kashmir or its merger with Pakistan since 1989.

However, Monday's attack came in the neighboring Punjab state, which witnessed militancy by Sikhs in the 1980s.