Yemen is to stop issuing visas to foreigners arriving at international airports. The state media has said the move is to halt terrorist infiltration. <br/><br/>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.