The U.S. Embassy in Riyadh and two other diplomatic missions in Saudi Arabia will remain closed for consular services due to security concerns, the embassy said in a statement Thursday.

The diplomatic facilities in Riyadh, Jiddah and Dhahran have been closed since Sunday. A security message to U.S. citizens encouraged them to be aware of their surroundings, avoid large gatherings and keep a low profile.

A statement emailed to The Associated Press said officials will continue to assess and coordinate with Saudi authorities and come to a decision “at the appropriate time” about when to resume consular services.

Last week, the embassy warned citizens that individuals associated with a terrorist organization could be targeting Westerners, including U.S. citizens, working for oil companies in the Eastern Province. The warning, issued late Friday, said officials received information about a threat to kidnap and attack workers.

The embassy said it had “no further information on the timing, target, location or method of any planned attacks.”

Earlier this month, another security message specifically warned employees working for Chevron in Saudi Arabia of a possible attack.

From 2003 to 2007, al-Qaida-linked radicals carried out attacks in Saudi Arabia aimed at destabilizing the Western-allied monarchy, including deadly bombings of residential compounds housing foreigners. The breakaway Islamic State group has urged its supporters to launch attacks inside the kingdom. Saudi Arabia is part of the U.S.-led coalition bombing the radical group in Iraq and Syria.

In November, a Saudi man stabbed a Canadian citizen while he shopped in a mall with his family in the Eastern Province. Also late last year, IS group supporters shot a Danish citizen in his car in Riyadh as he left work. Both men survived the attacks. SAPA