BERLIN: The European air safety agency has warned airline operators to show "extreme caution" when flying over Pakistan amid fears of possible terror attacks.

The European Aviation Safety Agency (EASA) "recommends all operators to exercise extreme caution" when flying over the country and not to fly below 24,000 feet (7,300 metres), it said in a bulletin on its website dated January 22.

The appeal by EASA, which does not refer to any specific threat of attack, applies to flights into, out of or within Pakistan airspace, it said.

It said that "national aviation authorities are reporting an increased risk to flight operation safety due to potential terrorist attacks in Pakistan".

Pakistan's Civil Aviation Authority (CAA) said it had issued no safety advisory and insisted its airspace was "safe and secure for all airlines".

"Issuance of any such guidance by any authority or doubt on the safety of Pakistan air space is, therefore, absolutely baseless," the CAA said in a statement.