Moscow (CNN) -- A "small-scale blast" occurred Wednesday at a Moscow public transportation stop, but there were no injuries or fatalities, officials said.
The blast occurred about 4:30 p.m. (8:30 a.m. ET), said Nikolai Sintsov, spokesman for the Russian National Antiterrorist Committee. A few cars parked near the stop sustained minor damage, he said, but "we are not dramatizing this event."
Russian news agencies earlier reported a bomb exploded at a bus stop near the building of the Academy of the Federal Security Service in southwest Moscow.
A group of investigators and forensic experts were sent to the blast scene "to study the causes and circumstances of the explosion," Russia's Investigative Committee said on its website.
Police were ordered to step up patrols in public areas including bus stops, Moscow police spokesman Viktor Biryukov told the Russian news agency Interfax.