The United States Embassy in Saudi Arabia warned US citizens to exercise caution in the area around the king’s palace in Jeddah on Saturday after reports on social media of an attack there.

According to social media, Saudi security forces foiled an attack near the Al-Salam Palace in the coastal city, leaving one attacker and two royal guards dead.

“Due to the possibility of ongoing police activity, American citizens are advised to exercise caution when travelling through the area,” the embassy warned.

The palace is located next to the King Abdulaziz Road and Andalus Road on the waterfront of the city.

The Saudi government has not issued an official statement confirming the incident.

Groups such as al-Qaeda and more recently the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) have carried out a number of attacks in Saudi Arabia.

Attackers have targeted Shia mosques in the country’s eastern provinces where much of its Shia minority is based, as well as security forces.

In July this year, Saudi authorities said they foiled an attack on the Grand Mosque in the Muslim holy city of Mecca, which they blamed on ISIL.

Hundreds of Saudi citizens have travelled to Syria to join the group.