Two Saudi Arabian policemen have been killed after a shooting in the country's capital Riyadh, according to the country's official news agency.

The pair were shot in an eastern district of Riyadh while on patrol in their vehicle early on Wednesday, the Saudi Press agency reported citing an unnamed police spokesperson.

The dead officers were named as Thamer Amran al-Mutairi and Abdulmohsen Khalaf al-Mutairi, according to the Reuters news agency.

Last month two policemen were shot and injured in a similar attack in Riyadh.

The authorities are carrying out an investigation into the shooting, the spokesman said.

No one has claimed responsibility for the attack, but groups such as the Islamic State in Iraq and the Levant (ISIL) and al-Qaeda have called on followers in the country in the past to attack targets including the authorities, non-Muslim residents and members of Saudi Arabia's Shia minority.

Some Saudi Shia Muslims have also carried out gun and petrol bomb attacks on police in Qatif, a district in Eastern Province, in retaliation for alleged systematic discrimination against members of the community.

Saudi Arabia denies all charges of discrimination.

Source: Reuters