A Czech doctor was kidnapped by gunmen in Yemen's capital Sanaa on Saturday, the third foreigner to be snatched this month, security sources said.
The doctor was walking to work at a private hospital when the armed assailants blocked her way with their car and seized her, the sources said.
The kidnapping, which highlights the increasing breakdown of security in the U.S.-allied country, follows that of a British oil worker by unidentified gunmen and a German abducted by Yemeni tribesman to press for the release of their jailed relatives.
Also on Saturday, an intelligence officer was killed by suspected al Qaeda militants in Yemen's southern province of Shabwa.
Colonel Ahmed Hashem was shot dead by the armed gunmen in the city of Atak, a security source said.
Yemen, which neighbours oil giant Saudi Arabia and is home to an active al Qaeda offshoot, has long wrestled with instability, internal conflicts and poor governance.
Protests in 2011 forced former president Ali Abdullah Saleh to end his more than three decades in power, but a political transition process has yet to calm a rebellion by Shi'ite Muslims in the north and a secessionist movement in the south.
Elsewhere, attacks blamed on al Qaeda-linked militants have grown bolder, raising fears of a total security breakdown.