A homicide bomb attack targeting Indian road construction workers and their Afghan police escorts left seven dead and 12 wounded Thursday in southwestern Afghanistan, an official said.

The convoy had been traveling on a main road toward the city of Khash Rod in Nimroz province when it was first hit by a remote-controlled bomb that was planted on a motorcycle, wounding one policeman, said Nimroz Gov. Ghulam Dastagir Azad.

The convoy stopped after the primary explosion, and a suicide bomber set off a secondary attack, leaving six policemen and an Indian worker dead, Azad said. Ten policemen and two Indian workers were wounded.