Two militants were killed in an explosive-packed car shortly after they tried to approach the entrance of a building of the National Security Directorate (NDS) intelligence agency in Shirpoor area, Xinhua reported.
A police officer said the bomb disposal squad defused the car bomb.
Initial investigation showed three men were involved in the incident, and security forces are trying to capture the last suspect in the area.
No group has claimed responsibility but Taliban insurgents were suspected of carrying out such attacks.
Earlier, two NDS service members and a police officer were killed and a policeman and three intelligence officials were wounded in two separate car bombings in Nangarhar and Logar provinces.
The Taliban claimed responsibility for the two bombings.
The Taliban ruled Afghanistan before they were ousted by a US-led invasion in late 2001.
Kabul: Afghan security forces shot dead two would-be suicide bombers Sunday, foiling a terror attack in a diplomatic enclave here, police said.
First Published: Sunday, February 24, 2013, 15:37