For consecutive fifth day, Pakistan International Airlines (PIA) has received a bomb threat on Monday, which disturbed its flight Karachi-bound flight. According to sources, a call from an unknown number was received at Allama Iqbal International Airport that a bomb had been planted on a PIA flight PK-303. The security agencies searched the aircraft and no bomb was found. After a security clearance it took-off at 2.35 pm. A case has been registered against an unknown caller.