An Indian Air Force aircraft with 13 people on board went missing on Monday. The plane, which had taken off from Jorhat in Assam, lost contact with ground controllers 33 minutes later.

The AN-32 transport aircraft, which was to land at the Menchuka airfield in Arunachal Pradesh, took off around 12.27 pm and lost all contact with ground staff around 1 pm, the Indian Air Force said. Those on the aircraft comprised five crew and eight passengers, ANI reported.

“An IAF AN-32 took off from Jorhat at 1227 hrs for Menchuka ALG,” the Indian Air Force tweeted in the evening. “Aircraft last contacted ground control at 1300 hrs. There was no further contact with the aircraft. Efforts are on to establish the whereabouts of the aircraft.”

The air force said a C-130 jet, another AN-32 aircraft and an Mi-17 fighter jet have been dispatched for search operations. An Indian Army helicopter is also accompanying the planes.

“Some reports of possible location of crash site were received, however, no wreckage has been sighted so far,” the air force added. “IAF is coordinating with Indian Army, various government and civil agencies to locate the missing aircraft. Search operations will continue from air and by ground parties of Indian Army through the night.”

In 2016, an IAF AN-32 plane disappeared while flying over the Bay of Bengal after taking off from Chennai for the Andaman and Nicobar Islands, NDTV reported. The aircraft was never found, and all 29 people were presumed dead.