The Russian Foreign Ministry issued a travel warning on Tuesday, July 24, advising Russian nationals to refrain from traveling to Syria, RIA Novosti reports.

“Owing to the extremely tense situation in Syria, the ongoing fighting in different parts of the country between government troops and the armed opposition, the Russian Foreign Ministry strongly recommends that Russian citizens refrain from visiting the Syrian Arab Republic,” the warning said.

It also stated that Russian air flagship Aeroflot will halt service to Damascus from August 6.

The United Nations, quoting Syrian rights activists, says some 16,000 people have died in Syria since the start of the now almost 18-month revolt against Syrian President Bashar al-Assad.