Governments, airlines and aviation authorities around the world were reviewing security on Monday after US-bound parcel bombs, sent by air from Yemen, were intercepted in Dubai and Britain.
In London, Prime Minister David Cameron convened a crisis committee meeting to decide Britainâ€™s response after one of the packages was found on a United Parcel Service cargo plane at East Midlands Airport, north of London, on Friday.
The other bomb was discovered in a computer printer cartridge in a parcel at a FedEx facility in Dubai.
The findings exposed what appeared to be a loophole in air cargo security that put passengersâ€™ lives at risk.
â€œAir freight is still considered to be the soft underbelly of the aviation industry,â€ aviation security expert, Chris Yates, told BBC television.
Qatar Airways confirmed the Dubai parcel had been transported on its passenger planes from Sanaa via Doha.
Nigeria said it would inspect all cargo heading for the United States with scanners for detecting explosives, in addition to its normal X-ray screening procedures.
Cameron said on Saturday the bomb found in Britain was designed to blow an aircraft out of the sky.
The plot could fuel calls for the wider use of imaging technology designed to detect explosives, which is not standard; but freight firms are reluctant to bear the full cost.
Tighter international air cargo security rules could deal a blow to trade and the world economy.
Freight firms clashed with U.S. and European policy makers last year over calls for 100 percent scanning of sea containers. Plans to introduce full scanning from 2012 were postponed.
British Home Secretary, Theresa May, who was due to brief parliament on the bomb plot later on Monday, said on Sunday, security around all international air cargo arriving in Britain would be reviewed.
Britain said it had immediately halted the movement of air freight from Yemen into or through Britain, including cargo brought in on indirect flights from the country. Direct flights from Yemen to Britain had already been suspended.
Michael Oâ€™Leary, chief executive of Europeâ€™s largest budget airline, Ryanair, called for a common sense response, saying imposing further security restrictions on passengers would be ineffective.
â€œWeâ€™ve had ludicrous regulations in the past couple of years where we are confiscating womenâ€™s lipsticks and bottles of water over 100 ml, making people take their shoes off. It has no effect on security whatsoever,â€ he told BBC television.
Restrictions on the carrying of liquids on planes were introduced in 2006 after the discovery of an al Qaeda-inspired plot to blow up trans-atlantic flights with explosive materials concealed as soft drinks