Four suspected militants were killed on Wednesday, 17 August, during a counterterrorism raid in St Petersburg, Russian security forces announced. The raid was carried out in an attempt to arrest suspected members of terrorist groups from the North Caucasus, Russia's Investigative Committee said.

In a statement, committee spokesman Vladimir Markin said that the heavily armed Federal Security Service (FSB) officers were met with gunfire as they attempted to enter the flat on Leninskii Prospekt.

Officers ordered the men to surrender but a shootout occurred instead. The four suspects were killed during the shootout with officers, according to the statement.

The counterterrorism committee added that three of the men killed had been wanted after being linked to a series of terror attacks and attempted assassinations, the BBC reported.

According to ABC News, social media was abuzz with posts showing approximately two dozen police in body armour and helmets surrounding the apartment block. Officers blocked off the building but said no civilians were injured during the raid.

RIA Novosti, a Russian news agency, initially reported that three suspects were detained but the Investigative Committee clarified that they had been killed in the shootout. A criminal investigation regarding the possession of firearms and explosives has also been opened, ABC News reported.

The BBC reported that three of the men were provisionally identified as Zalim Shebzukhov, Astemir Sheriev and Vyacheslav Nyrov. The committee said the men were leaders of a "terrorist underground" active in Kabardino-Balkharia region of the North Caucasus.

ABC News noted that Russia has been on high alert since its military intervention in Syria. The Islamic State (Isis) has promised to retaliate for its involvement with strikes on Russian soil.

Russia has also battled against jihadist militant groups in the North Caucasus for over a decade. Militant groups in Chechnya and Dagestan, linked to both al Qaeda and IS (Daesh) have pledged attacks against Russia.