Two US citizens came under gunfire on Friday in Saudi Arabia, and one of them was wounded but "in stable condition," police said.
It was not immediately known who shot at them.
The two were traveling on a road in the Eastern Province governorate of al-Ahsa at the time, said a police spokesman in a statement published by the state run SPA news agency.
This is the fourth recent attack on foreigners in the kingdom, which joined a US-led coalition against the Islamic State of Iraq and Syria (ISIS) in September.
In December, Saudi authorities arrested three ISIS supporters for shooting and wounding a Dane in his car in Riyadh.
That same month, an assailant stabbed and wounded a Canadian while he was shopping at a mall in Dhahran on the Gulf coast.
Canada and Denmark are also taking part in the air campaign against ISIS.
In October, a Saudi-American who had been fired from his job with a US defense contractor shot dead an American and former colleague and wounded another in Riyadh.
In November, Saudi Arabia blamed ISIS-linked suspects for the killing of seven persons, including children, in Eastern Province.
Saudi Arabia's air force participated in US-led bombing strikes against ISIS since September. Jordan, Bahrain and the United Arab Emirates are also participating in the bombing led by the US.
It is the first time since the 1991 Gulf War that Arab states have made common cause to join US-led military action.
