A Pakistan International Airlines aircraft carrying 266 people came close to colliding with a domestic airliner, an official said on Thursday, the second near miss over southern Pakistan in six months.

A warning system on the PIA Boeing 747, which was flying from Karachi to New York on Tuesday, alerted the pilot to an oncoming Airbus A320 aircraft of domestic carrier Airblue, a PIA spokeswoman said.

"They were only a few nautical miles away in the same air corridor," said Samina Pervez and added the PIA plane went into a steep dive to avoid a collision.

None of the passengers or crew on board the two planes was hurt.

There were 146 passengers and crew on the Airblue flight from the Pakistani capital Islamabad to Karachi.

A similar incident involving planes from the two airlines took place in December, also over southern Pakistan.

Pakistan's civil aviation officials have started an inquiry into Tuesday's near miss. An investigation into the incident in December has not yet been completed.