ANKARA - A Turkish Airlines plane bound for Switzerland returned to Istanbul on Friday after a bomb threat, local Daily Sabah reported.

The Boeing 738 aircraft, which was carrying 151 passengers, was called back to Istanbul while flying over Bulgarian, according to the report.

This is the third time that Turkish Airlines flights have to take emergency measures against bomb threats during the past less than a month.

On April 1, a Turkish Airlines passenger plane flying from Istanbul to Lisbon, the capital of Portugal, returned to Turkey over a bomb alert.

On March 30, another Turkish Airlines plane traveling from Istanbul to Brazil's Sao Paulo made an emergency landing in Morocco's Casablanca international airport due to a bomb scare.