A military convoy belonging to the NATO-led International Security Assistance Force (ISAF) coalition was bombed outside its base in Kabul's diplomatic quarter on Saturday, but no troops were hurt, security sources and ISAF said.
The base is close to both the German and Italian embassies.
Security sources said the bomb had targeted a military convoy close the entrance of the base, but ISAF's statement said only that there had been "an improvised explosive device detonation in the vicinity of Camp Eggers."
"Initial reporting does not indicate any International Security Assistance Force (ISAF) casualties," the satement added.
Reuters reporters heard sirens and helicopters flying overhead, and a loudspeaker announcement ordered troops at the base to load their weapons and take up defensive positions.
Meanwhile, ISAF said one of its service members has died following a suicide bomb attack by insurgents on a joint NATO-Afghan base in Nangarhar province in the eastern part of the country.
NATO did not identify the service member's nationality.
Officials said five other insurgents were also killed Saturday when they tried to storm the base in Nangarhar's Ghani Khail district after the suicide bomber struck.
The Taliban has claimed responsibility for both attacks.
Afghan militants have intensified attacks recently in a campaign to regain territory as foreign forces prepare to leave at the end of 2014.
Some information for this report was provided by Reuters.