Britain suspended direct flights with Yemen on Wednesday and the prime minister said the U.K. will introduce new no-fly lists as it seeks to tighten airport security following the failed Detroit airliner attack.

Prime Minister Gordon Brown told the House of Commons the measures are in response to a growing threat from Al Qaeda affiliated terrorists based in Yemen.

"We know that a number of terrorist cells are trying to target Britain and other countries" from Yemen, Brown told lawmakers, following a meeting Tuesday with Britain's military, intelligence and border security chiefs.

Brown said Britain will draw up extended lists of suspects banned from flying through the U.K., and create an enhanced screening program targeted at some other passengers. He did not specify which groups would be targeted for enhanced checks.

"The security of our citizens must be our priority," Brown told legislators.

He said Yemen is "an incubator and safe haven" for terrorists, and with Somalia poses the most significant terrorist threat to the world after the Pakistan border areas. Somalia and Yemen are separated by the Gulf of Aden, one of the world's most pirate-infested waterways.

Brown discussed the threat posed by Yemen and "ongoing cooperation in the fight against terrorism" in a telephone call Tuesday night with President Barack Obama.

A decision to increase airport security follows the failed Christmas Day attack on a plane from Amsterdam that was preparing to land in Detroit.

Umar Farouk Abdulmutallab, a Nigerian alleged to have links to extremists based in Yemen — and formerly a student in London — is accused of attempting to blow up the Northwest Airlines flight using concealed explosives. He failed to ignited the explosives.

Brown has also called for the greatly expanded use of full body scanners at U.K. airports in response to the continued threat from attempts to attack airliners.

Britain's Foreign Office said direct flights to Yemen had been halted on security grounds, and British officials were working with the Yemeni government to strengthen airport passenger checks.

Foreign Office minister Ivan Lewis said flights will only be resumed once airport security is improved in Yemen.

"The first responsibility of any government is the security of its citizens," he told legislators.

Foreign ministers — including Secretary of State Hillary Clinton — are expected to attend talks in London on Jan. 27 on the threat posed by Yemen.