British Prime Minister David Cameron has called on the Arab world to help fight against terrorism as investigations continue into two United States-bound parcel bombs discovered en route from Yemen.
Mr Cameron told Parliament the Arab world needed to cut out the terrorist cancer in its midst.
One of the devices was found at a Midlands airport, prompting several European countries to tighten air security. Germany has announced a total ban on direct flights from Yemen, while the Netherlands has suspended cargo and mail flights from there.
For its part, Britain has banned air freight from Yemen, and suspended air cargo from Somalia.
Britain has also banned air passengers from carrying printer cartridges in their hand luggage. The explosives found at the weekend were disguised as cartridges.
It has also announced a review of all aspects of British air freight security.
One of the bombs was carried aboard two passenger planes before being seized in Dubai. The other was located in Britain after an intelligence tip-off from Saudi Arabia.
Meanwhile, a hunt continues in Yemen for Ibrahim Hassan al-Asiri, the man believed to have made the bombs.
He is believed to have made a bomb intended to blow up an aircraft landing in Detroit on Christmas Day last year.
British officials say the crucial tip-off came from an al Qaeda member who handed himself into Saudi authorities two weeks ago. He was reportedly one of several former detainees at the US detention centre at Guantanamo Bay, Cuba, who were returned to Saudi Arabia in December 2006.