Russia told its citizens to leave Syria amid escalating violence on Tuesday. It cautioned its nationals to use extra care because both army and commercial planes are being targeted around the country.

Moscow is also refusing to meet Syrian requests for certain arms shipments — including more of the training planes that President Bashar Assad’s regime has been utilizing as bombers, and intercontinental-range SS-17 ballistic missiles — Israel’s Channel 2 News reported Tuesday. Russia, which has been supplying the Syrian regime with weapons for over four decades, has been criticized in the West for aiding Assad in the bloody 18-month uprising.

Moscow had previously hinted it will not send the regime any more weapons, adding that shipments to date represent its fulfillment of existing arms agreements rather than new arms deals.

Russia is also reported to be contemplating scaling down operations at its military base in Tartus, western Syria, if the security situation becomes critically dangerous.

According to independent Russian news agency Interfax, Russia admitted it had previously considered evacuating personnel from Tartus, but decided the situation was stable enough to stay.

Tartus, Russia’s only naval facility outside the landmass that comprises the former Soviet Union, is referred to as Moscow’s gateway to the Mediterranean. It hosts storage facilities, military specialists, and ships that come to be resupplied.