NEW DELHI — Al Qaeda has released a video announcing the establishment of a new branch on the Indian subcontinent, saying it is meant to revive jihadist activity in a region that was once “part of the land of Muslims, until the infidel enemy occupied it and fragmented it and split it.”

In the 55-minute video posted on jihadist forums, Al Qaeda’s leader, Ayman al-Zawahri, addresses listeners in parts of the region with large Muslim populations, assuring Muslims in Burma and Bangladesh; in the Indian states of Assam and Gujarat; and in the Kashmir region that “your brothers” in the militant organization “did not forget you and that they are doing what they can to rescue you.”

In recent months, Al Qaeda’s emerging competitor, the Islamic State in Iraq and Syria, has begun to recruit Indian Muslims, and some analysts viewed the video announcement as a response. The new entity, Qaedat al-Jihad in the Indian Subcontinent, represents the network’s fifth official branch and its first in Asia, adding to branches based in North Africa, in East Africa, in Yemen and in Syria.

Mr. Zawahri said it had taken more than two years “to gather the mujahedeen in the Indian subcontinent into a single entity,” but did not mention smaller groups that might be affiliated. The SITE Intelligence Group, which monitors extremist activity online, said the video was posted Wednesday.