India tightened security on the border with Pakistan on Monday after heavily armed men stormed a police station in the northern frontier state of Punjab, killing at least seven people and wounding several others.

Armed police exchanged fire with the gunmen, who were holed up in the police station in Gurdaspur district more than eight hours after the assault began at about 5 am, officials said.

Gunshots were heard on television as security forces in red turbans surrounded the building in the town of Dinanagar, about 15 kilometers from the international border. Soldiers were also deployed, at least one armed with a shoulder-mounted rocket launcher.

"We have been able to limit, they are surrounded, they are holed up in the police station. We are on top of the situation," said Harcharan Bains, an adviser to Punjab's chief minister.

Monday's attack was the first such operation in Punjab in 13 years, according to data from the South Asia Terrorism Portal, which tracks militant violence.

India and Pakistan have fought three wars since both nations gained independence in 1947. Pakistan has denied any involvement in insurgencies in Punjab, and Islamabad's foreign office said it was not aware of any reports that the people involved in Monday's attack were Pakistani.

'Situation under control'

India's Federal Home Minister Rajnath Singh said he had spoken to the head of India's Border Security Force and "instructed him to step up the vigil" on the border.

"The situation is under control," Singh said.

Harchanran Singh Bains, a Punjab state government spokesman, said two of the dead were militants. It was not immediately known if all of the other five were police.

The group of about five attackers came in a white Maruti-Suzuki car, dressed in army uniforms, a local politician said, adding that the attackers took the vehicle at gunpoint from a roadside dhaba restaurant.

India fought a deadly Sikh insurgency in Punjab in the 1980s that peaked with the assassination of Prime Minister Indira Gandhi at the hands of her Sikh bodyguards in 1984.

That attack was in retaliation for her decision to order the army to flush out militants from the Golden Temple in Amritsar, the holiest shrine of the Sikh community.

Reuters - AP