Islamist militants attacked a Yemeni army base on Monday, killing 20 soldiers and capturing 25 just hours after a US drone strike killed a senior militant.
The militants reached the base in Abyan, southern Yemen, from the sea and by land, gunning down troops and stealing weapons and other military hardware.
Government forces later shelled militant positions elsewhere in the province, killing 16.
It was not immediately clear if the pre-dawn militant raid on the Abyan base was in retaliation for the assassination of Fahd al-Quso, a top al-Qaida leader wanted by the FBI.
As Aslef's annual assembly of delegates begins in Edinburgh tomorrow the general secretary explains the challenges his members - and workers across the country - face