A "complex" ambush involving a suicide bombing and ensuing fire killed 16 civilians and wounded 24 others as well as a coalition soldier in eastern Afghanistan on Sunday, a coalition statement said.

A suicide car bomber targeted a coalition convoy, which locals said was a U.S. military convoy, outside Jalalabad city, capital of Nangarhar province, in the morning, Afghan officials said.

The bombing was followed by enemy small-arms fire from several directions, the statement said, adding "Coalition forces returned fire in defense of the patrol."

"Sixteen civilians died during the initial attack, including four civilians who later died of their wounds," said the statement, adding 24 civilians and a coalition soldier were also wounded during the attack.

However, the statement did no clearly tell how the civilians were killed or injured.

The Afghan police earlier said U.S. soldiers opened fire toward Afghans on the road after the blast, killing eight civilians and injuring dozens.

"The incident remains under investigation by Afghan and coalition forces," the statement said.

Hundreds of Afghans blocked the road, threw stones toward Afghan policemen who were sealing off the scene, and chanted against the U.S. forces.

Due to rising Taliban-linked insurgency, more than 400 persons have been killed in violence and clashes in Afghanistan this year.

Editor: Yan