A policeman has opened fire at a police training centre in Jordan, killing two Americans, a South African and two Jordanians, officials say.

The Jordanian embassy in Washington said the Jordanian assailant also wounded two Americans and two Jordanians, before being shot dead.

President Barack Obama said the US was taking the attack "very seriously".

The US-funded Jordan International Police Training Centre (JIPTC) hosts mainly Palestinian and Iraqi officers.

Civilian contractors from the US and elsewhere assist Jordanian police trainers at the facility in Muwaqqar, on the eastern outskirts of Amman.

Jordanian government spokesman Mohammed Momani told the Associated Press that an investigation had been launched into whether the motive for Monday's shooting attack at the JIPTC was personal or political.