Foreigners who want to enter Yemen can no longer obtain a visa at its airports.

The measure has been taken by the government in Sana'a to prevent militants entering the country. From now on, visas will only be issued by Yemeni embassies in the country of departure, as the screening at embassies is more thorough than at airports.

Western tourists have also been affected by the measure. Up until now they could apply for a visa on landing at one of Yemen's six international airports.

The Middle Eastern country is under pressure to take measures against terrorism, since the failed attempt to bomb a US airliner on Christmas Day. The would-be bomber, Umar Farouk Abdulmutallab, said he was trained in Yemen by a branch of al-Qaeda.

On Wednesday, British Prime Minister Gordon Brown announced the suspension of all direct flights from Yemen to Great Britain.

Photo Yemeni capital Sana'a - Flickr/eesti