A Boeing 737-800 passenger aircraft operated by Russia’s S7 Airlines, flying from Novosibirsk to Makhachkala, declared an emergency while in Kazakh airspace on Monday.

Axar.az reports, citing Russian media, that emergency services said the aircraft abruptly changed course and headed toward the Russian border.

According to Flightradar24, the aircraft was operating flight S7 7099 and had set its transponder to emergency code 7700.

An S7 Airlines representative later told Interfax that the plane was heading to Omsk Airport due to a technical malfunction.

“The crew of flight S7 7099, operating from Novosibirsk to Makhachkala, decided to land at an alternate airport in Omsk due to a technical malfunction. The aircraft is preparing to land,” the representative said.

The Boeing 737-800 can accommodate up to 189 passengers. The actual number of people on board is being confirmed.