ISLAMABAD: Pakistani officials on Saturday accused Indian troops of "unprovoked" cross-border firing in the disputed Himalayan region of Kashmir, triggering an intense exchange of fire in which three civilians were killed and three others wounded.

According to police official Mohammad Shafqat, three members of a family, which included two sisters and their brother, were "martyred" in Pakistani Kashmir. A fourth person who was critically wounded this week died at a hospital, he said.

Pakistani troops are returning fire and carrying out a "befitting response," the military said in a statement.

However, an Indian army officer Saturday blamed Pakistan for initiating the firing, and also described the Indian troops' response as "befitting". The officer spoke on condition of anonymity as he was not authorised to brief reporters.

Although such shootouts are common, the latest one came a day after Pakistan's navy said it had intercepted Indian submarines entering the country's territorial waters in the Arabian sea. India quickly denied the claim.

Pakistan's foreign ministry spokesman, Nafees Zakaria, posted a tweet to express his sympathies for those who lost their loved ones in the cross-border firing.

Pakistan has said India is escalating tension to divert the world community's attention from its human rights violations in Indian-controlled Kashmir, and says its army responds with restraint when under attack.