Yemen is to stop issuing visas to foreigners arriving at international airports, state media has reported.
The move was to “halt terrorist infiltration,” Saba state media said.
The change will affect Western visitors, including those from the US, Canada and Europe, who had generally been able to get visas at airports.
Al-Qaeda in the Arabian Peninsula, based in Yemen, apparently trained a Nigerian man charged over the failed bomb attempt on a US plane last month.
There has been increasing pressure on Yemen to crack down on al-Qaeda in the wake of the 25 December plot.
According to the Yemeni defence ministry newspaper September 26, a military official said “granting visas to foreigners will take place only through the embassies of Yemen, and after consulting security authorities to verify the identities of travellers”.
This is to “prevent the infiltration of any suspected terrorist elements,” he was quoted as saying.
Six airports in Yemen receive international flights, AFP news agency reported.
Separately, the US said there were concerns that al-Qaeda in the Arabian Peninsula was expanding its recruitment efforts “to attract non-traditional followers”.
The US Senate foreign relations committee, in a report released on 21 January into al-Qaeda in Yemen and Somalia, said there were concerns about some Americans who “had disappeared and are suspected of having gone to al-Qaeda training camps in ungoverned portions of the impoverished country”.
Law enforcement officials believed there could be as many as 36 US citizens who converted to Islam while in US prisons and travelled to Yemen in the past year, “possibly for al-Qaeda training”.
There were also up to a dozen US citizens who had married Muslim women and converted to Islam who had also gone to Yemen, but there was no evidence they had undergone training, the report said.
“But [officials] said they are on heightened alert because of the potential threat from extremists carrying American passports,” the report added.
The report said one official described them as ”blond-haired, blue eyed types”.
“These individuals fit a profile of Americans whom al-Qaeda has sought to recruit over the past several years,” the report said.