ABUJA (Reuters) - A Nigerian airline involved in the country's deadliest air crash for 20 years has been suspended from flying just six months after it was allowed to restart, the airline said on Sunday.

Dana Air said in a statement it did not know the reason for the suspension by the Nigerian Civil Aviation Authority (NCAA).

In June, Dana Air flight 992, a McDonnell Douglas MD-83, crashed into an apartment block in a populated Lagos suburb, killing 153 people on board and 10 others on the ground.

Dana was suspended, but was allowed to start flights again in September, despite an inquiry into the cause of the crash not yet being complete.

Nigeria's President Goodluck Jonathan sacked the head of the aviation authority last week and has proposed a replacement to the Senate.

(Reporting by Camillus Eboh; Writing by Tim Cocks; Editing by Matthew Tostevin)