RIYADH (REUTERS) - A Danish man was shot and wounded in the Saudi capital Riyadh on Saturday by an unknown assailant as he left work in his car, state news agency SPA said.

The victim, who was shot in the shoulder, was taken to hospital and is in a stable condition, a Riyadh police spokesman told the news agency. An investigation was underway, he said.

The attack comes a month after an American citizen was shot dead in Riyadh and another was wounded.

Police have said initial information showed the gunman who killed the American had no ties to extremist groups.

Saudi officials have said this year they are concerned about a rise in domestic Islamist militancy due to the conflicts in Iraq and Syria.

The government has decreed tough penalties for terrorist crimes.

Two weeks ago, eight people were killed in the al-Ahsa district of Saudi Arabia when an armed group attacked Shi'ite Muslims marking the religious anniversary of Ashoura.