The UN Security Council on Tuesday "strongly condemned" a deadly terrorist attack in southeastern Yemen, which killed 20 Yemeni soldiers.

In a statement released to the press, the 15-nation UN body said: "any acts of terrorism are criminal and unjustifiable regardless of their motivation."

"The members of the Security Council reaffirmed that terrorism in all its forms and manifestations constitutes one of the most serious threats to international peace and security, and that any acts of terrorism are criminal and unjustifiable regardless of their motivation, wherever and whenever and by whomsoever committed," it said.

Suspected al-Qaida militants on Monday attacked a security checkpoint in southeastern Yemen, first sending in a suicide car bomb then storming it, reports said.

The surprise attack was launched near the town of al-Rayda in Hadramawt province, at least 20 members of the Central Security Forces were gunned down while asleep in their quarters nearby.