There were no reported casualties, and Islamabad did not immediately confirm the gunfire from Pakistan.

India has accused Pakistan of supporting "cross-border terrorism" after gunmen killed 26 people last week, the worst attack on civilians in contested Muslim-majority Kashmir for a quarter of a century.

Islamabad has denied any role, calling attempts to link Pakistan to the attack "frivolous" and vowing to respond to Indian action.

"During the night of April 27-28... Pakistan Army posts initiated unprovoked small arms fire across the Line of Control", the Indian army said in a statement, referring to the de facto border in contested Kashmir.

"Indian troops responded swiftly and effectively," it added.

After the April 22 attack, New Delhi downgraded diplomatic ties, withdrew visas for Pakistanis, suspended a water-sharing treaty, and announced the closure of the main land border crossing with Pakistan.

In response, Islamabad ordered the expulsion of Indian diplomats and military advisers, cancelled visas for Indian nationals and barred its airspace to Indian airplanes.

The United Nations has urged the arch-rivals to show "maximum restraint" so that issues can be "resolved peacefully through meaningful mutual engagement".