The Indian Army was giving a befitting reply and heavy exchanges were on, they added.
Pakistani forces opened unprovoked heavy firing and shelling along the LoC in Bhimbher Gali sector of Rajouri district this evening, senior Army officials said on Sunday.
In the shelling, three jawans were killed, they said. An officer, who was injured in the shelling, also succumbed to his injuries, they added.
Six days before his birthday, 22-year-old Captain Kapil Kundu, a resident of village Ransika in Haryana's Gurgaon district, was killed in the shelling, Army officials said on Sunday.
23-year-old Captain Kapil Kundu martyred in Pak firing, Know all about the braveheart
Forty two-year-old Havildar Roshan Lal, resident of Samba district, 27-year-old Riflemen Ramavatar of Gwalior in Madhya Pradesh and Subham Singh (23) of J&K's Kathua district were also killed, he said.
"Martyrdom of Indian Army soldiers will not go in vain. The unprovoked action by the Pakistan Army will be given a befitting response," an official said.
Earlier in the day, two teenagers and a jawan were injured in Shahpur sector of Poonch district in shelling from across the border, a police official said.
He identified the injured civilians as Shahnaz Bano (15) and Yasin Arif (14), residents of Islamabad village.
A defence spokesman said the Pakistan Army initiated unprovoked and indiscriminate firing of small arms, automatic weapons and mortars around 1110 hours.