KABUL: Six American soldiers serving with Nato forces were killed by a roadside bomb in Afghanistan on Sunday, the alliance's military in Kabul and an American official said.

“Six International Security Assistance Force service members died following an improvised explosive device attack in eastern Afghanistan today,” ISAF said in a statement, without naming their nationalities or giving any further details.

In Washington, an official said the dead were Americans.

Another Nato soldier died in a similar attack earlier Sunday, ISAF announced, taking the day's toll to seven and the total toll for this year to at least 234, according to an AFP count based on the icasualties.org website.

As is traditional, ISAF deferred the identification of the casualties to their home countries.