Shiite militiamen seized three vehicles used by US embassy staff from Sanaa's international airport on Wednesday shortly after their departure from Yemen, officials said.
The vehicles were stolen from the airport by Huthi fighters following the evacuation of the US embassy in the capital, the airport and diplomatic officials said.
The US State Department said Wednesday it was suspending its Sanaa mission indefinitely due to Yemen's "deteriorating security situation".
Britain also evacuated its diplomats and France called on its citizens to leave the country, announcing it was closing its embassy from February 13.
The Huthi militia, which entered the capital unopposed last September, ousted Yemen's Western-backed president last week in a move denounced by some neighbouring states as a coup.