KARACHI, Pakistan, Nov. 6—The Pakistani Government said that tanks were used today in an attack on an East Pakistani border outpost, the first such reported use of Indian tanks in the border clashes that have been the subject of Pakistani statements for weeks.

A communiqué issued in Dacca said that the tanks joined Indian artillery and infantry in an attack by 450 Indian agents”—the official Pakistani term for East Pakistani secessionists—on a military post at Bantari, near Dinajpur. The communiqué said the attack was repulsed.

It said that Indian guns fired more than 450 shells at the post during the night. Early this morning, it said, Indian tanks shelled the area.