Heavily armed men dressed in military fatigues stormed a police station Monday in India's northern frontier state of Punjab close to the border with Pakistan, killing six people and wounding several others.

Police exchanged fire with the attackers, who remained holed up in the police station in Gurdaspur district 10 hours after the assault began at about 5 a.m., officials said.

There was a lull in shooting by early afternoon, a witness said, after security forces in red and black turbans surrounded the building in the town of Dinanagar, about 15 km from the international border.