At least 40 US troops have been
killed since April
The attack took place at a weapons collection centre in Baghdad, according to the Centcom statement.

"The soldiers were evacuated to a field medical facility for treatment, and one soldier later died of his injuries. The injured soldier is listed in critical condition."

"The soldiers were manning the weapons collection point when a van with four passengers stopped in a nearby alleyway approximately 250 metres (yards) from their location," the statement read.

"Two attackers exited the van, and each fired a rocket-propelled grenade at the squad," said Centcom, adding that the attackers fled down the alleyway.

They added that US forces launched a search of the area for the assailants. Names of the casualties were withheld pending notification of the next of kin.

At least 40 US troops have been killed since the fall of Baghdad on 9 April.

The month of May has seen the number of attacks on US occupying forces triple to 85 compared to the previous month.