A suicide bomber attacked a convoy of international troops near the airport in the southern Afghan city of Kandahar on Wednesday, a security official said, and the NATO-led military coalition confirmed there were casualties.
“We are working to gather additional information as quickly as possible and will release more details as appropriate,” the coalition said in a statement.
A local security official said the attacker drove an explosives-laden vehicle into the convoy. No further details were immediately available.
A Reuters witness at the scene said military helicopters landed at the site at least four times.
The airport in Kandahar is home to a major military base for international troops helping Afghan security forces.
The coalition maintains nearly 13,000 troops from 39 countries as part of a mission to train, advise and assist Afghan troops, who are struggling to contain a resurgent Taliban insurgency.
U.S. military commanders in Afghanistan have asked for several thousand additional troops, but the request is stalled in Washington, where President Donald Trump has expressed scepticism over extending the American commitment.