ISLAMABAD/SRINAGAR, India (Reuters) - Seven Pakistani soldiers were killed by Indian shelling across the frontier in the disputed Kashmir region overnight, Pakistan’s military said on Monday, as tensions between the nuclear-armed neighbors simmer.

Pakistan’s military media wing, ISPR, said in a statement the seven soldiers were killed in the Bhimber sector on the “Line of Control” de facto border in Pakistan-administered Kashmir.

A spokesman for India’s army said its soldiers had responded to Pakistani firing on Sunday night.

“There was a brief ceasefire violation initiated by Pakistani in Noushera sector which was effectively retaliated last night,” the spokesman told Reuters, declining to comment on any Indian casualties.

He also said there was ongoing firing between the two countries’ forces on Monday along another part of the frontier.

Relations between Pakistan and India have been strained for several months, while cross-frontier shelling has intensified in recent weeks leading to deaths of civilians and soldiers stationed along the disputed frontier.

Tensions have been fraught since July when India-administered Kashmir was rocked by street protests after the killing of a militant leader there.

Islamabad launched an international campaign to highlight alleged rights abuses by Indian security forces in Kashmir, while New Delhi blamed Pakistan for fanning the unrest.

New Delhi also blamed Pakistan-based militants for a deadly attack on an Indian army base in the region in September, a charge Islamabad rejected.

Several days later, India said it had carried out “surgical strikes” on militant bases across the border. Pakistan dismissed the claim as “an illusion”.

Kashmir lies at the heart of the tension between India and Pakistan and the countries have fought two of their three wars over the region since partition and independence from Britain in 1947.