A huge explosion hit a suburb of the Syrian capital Damascus that is home to a strategic military airport on Sunday evening, Syrian state TV reported.
A RIA Novosti correspondent reported that the blast could be heard outside the western Mezze neighborhood in other areas of the city.
Qatar-based broadcaster Al Jazeera said citing the UK-based Syrian Observatory for Human Rights (SOHR) there were unconfirmed reports of casualties but provided no figures.
More than 90,000 people are believed to have died since fighting broke out between Syrian government forces and rebels in March 2011, according to UN data.
Russia and China have faced widespread condemnation over their refusal to approve UN sanctions against Syrian President Bashar Assad’s regime. Moscow says it has no interest in seeing Assad remain in power, but is concerned unilateral sanctions would create a power vacuum that would lead to more violence.