All Pakistani airports were put on high alert on Thursday after an anonymous caller warned that they would be targeted today.

An emergency was declared at the Islamabad [Images] airport and the passenger lounges and car parks in the premises were evacuated following the threat.

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Civil Aviation Authority officials were quoted as saying by Dawn news channel that security was enhanced at airports across the country after an anonymous caller telephoned an official at the airport in the southern port city of Karachi and warned that airports in various cities would be targeted today afternoon.

The officials said that they had been alerted by intelligence agencies that a suicide bomber might target the Islamabad airport. All traffic to the airport was temporarily suspended.

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Interior ministry chief Rehman Malik told reporters that there was no suicide bomber within the Islamabad airport but 'the threat still exists'. "We have enhanced security at all airports across the country," Malik said.