The United States government issued a second security alert to its citizens in Saudi Arabia regarding the use of airports in the kingdom, following missile attacks on the country’s airports.

In a statement on Sunday, the U.S. embassy and consulates in Saudi Arabia said citizens were to follow the guidance of national alerts released by Saudi Arabia’s Civil Defense via cellular broadcast.

It said operations at King Khalid International Airport in Riyadh remained suspended, adding that King Abdulaziz International Airport in Jeddah and King Fahd International Airport in Dammam were operational, with some delays and cancellations.

“U.S. citizens should be aware of potential attacks on airports, airspace closures, flight cancellations, and travel disruptions. Please take extreme caution if you choose to use airports in Saudi Arabia,” the memo read.

It urged its citizens to check their flight departure status directly with the airline and with the airport.

“Private car, train, and bus options may provide alternatives to air travel to or from Saudi Arabia,” it said.

It explained that its citizens should confirm availability and schedules directly with the providers.

“Land border crossings, including the King Fahd Causeway to Bahrain, remain operational. All highways and roads in and around Riyadh, Jeddah, and Dhahran remain operational,” the embassy said.

The advisory stated that international airports in neighbouring Bahrain, Jordan, Oman, Qatar and the United Arab Emirates remained operational, while advising travellers to confirm their status directly with the relevant airports.

Saudi Arabia’s Ministry of Interior warned against “filming, publishing, or sharing information related to countering missiles and drones and their impact sites.

“U.S. citizens have been detained for not adhering to these regulations, including taking photos of government buildings, airports, and impact sites.”

It added that visitors and residents were subject to local laws while in Saudi Arabia.

This came after Australia, the U.S., and the UK warnedcitizens against travelling to Saudi Arabia over security concerns, citing threats to airports and disruption to air travel.

The Nigerian government and the African Union Commission had earlier condemned the attack carried out at King Khalid International Airport in Riyadh.