Three people were injured in central Moscow late Monday after an improvised explosive device was thrown at a group of bystanders at a bus stop, police said, according to Russian news services.

Two women and one man suffered light injuries in the attack, the state-run Tass news service reported, citing local police. The explosion was confirmed by the Moscow police press office, which didn't provide further details.

Russia has stepped up security since a series of terrorist attacks, including the downing of a Russian passenger jet in Egypt with 224 people on board in October and the massacre of 130 people in Paris last month, both claimed by Islamic State. Russian President Vladimir Putin started a military campaign in Syria more than two months ago to bolster Syrian President Bashar Assad and fight Islamic State and other jihadis.