NEW DELHI, April 28— Warning of potentially “serious consequences,” India filed a strong protest with Pakistan today over what New Delhi de scribed as several instances of “unprovoked firing on Indian territory.”

The Indian note Charged that on several occasions this week, Pakistani troops, who are seeking to crush an independence movement in East Pakistan, had fired into and crossed into Indian territory, killing at least seven villagers.

The note, handed to the Pakistan High Commissioner in New Delhi, Sajjad Haider, said the Indian Government was “constrained to advise the Government of Pakistan to ponder over the serious consequences that could follow from the repetition of such acts by the Pakistan Army.”

Another Pakistani border incursion, a shelling incident, was reported by the Indians today over 100 miles north of Calcutta. There were no reports of civilian casualties.

Meanwhile, In their diplomatic war over the independence struggle in East Pakistan, India denied a Pakistani charge that restrictions had been placed on the movements of the West Pakistani diplomats in Calcutta. And Pakistan denied the Indian charge that the Indian diplomats in Dacca, East Pakistan, had been “practically interned in their residences.”

Pakistan announced several days ago that she was closing her Deputy High Commission office in Calcutta because the mission was unable to func tion properly, and ordered India to close her office in Dacca on a reciprocal basis.

The Pakistani Mission in Calcutta was taken over by East Pakistani diplomats, who constituted a majority of the staff, and who converted it into the first foreign mission of the newly proclaimed government of Bangla Desh, which means Bengal Nation and is the name the Bengali independence movement has given to East Pakistan.

Pakistan is now demanding that India return the East Pakistani diplomats to Pakistan, while India says she cannot force them to leave.