Two suicide attacks against a counter narcotics office and the intelligence agency Thursday killed at least five people and wounded ten others in eastern Afghanistan, an official said.

A suicide attacker rammed his explosives-laden Toyota pick up truck into the entrance of the National Directorate of Security (NDS) in Khost city, the capital of Khost province, killing two agency employees.

"The suicide car bomb at the intelligence office martyred two intelligence workers and wounded three others," Tahir Khan Sabari, the deputy governor of Khost province, told AFP.

Separately, another suicide bomber wearing an Afghan army uniform and carrying an AK-47 machine gun tried to get into the adjacent counter narcotics building but was stopped by police guards who shot at him, he said.

"Police fired at him and explosives strapped to his body went off, killing three policemen and wounding seven others including three civilians," Sabari said.

Sabari said police were still looking for other militants who were also wearing army uniform and were reported to have entered the NDS offices right after the first suicide blast.

"Police are searching for more attackers but we are not sure if there are any other attackers in the area," he said.