Malaysia Airlines (MAS) has confirmed that it will tighten its security level in the air and on the ground which includes monitoring the airline's crew.

All flight deck crew are reported to have received a circular on the upgrade.

“Yes, MAS has upgraded its security level and in the air and on the ground.

“However, for security reasons we are not able to reveal the procedures,” said a representative of MAS Communications Department when contacted by Astro AWANI.

According to an earlier report by The Star, MAS has tightened its security by not allowing the pilot or co-pilot to be alone in the cockpit.

Under the new rules, a cabin crew should be in the cockpit until the pilot or co-pilot returns from the restroom.

The new rule also requires a flight attendant to stand guard at the door to ensure no passenger enters the restricted area when bringing food into the cockpit.

CNN had also reported of the rules which restricted pilot or co-pilot from being alone in the cockpit.