(VOVworld) – Russian news agency Interfax reports that several suspects have been arrested in connection with the deadly bombing on the St Petersburg metro three days ago.

Russian police have tightened security while citizens lay flowers in memory of the victims of the bomb attacks in Saint Petersburg on April 4. (Photo: EPA/VNA)

Russia's Investigative Committee says they have found clues at the houses of the suspects.

On Monday, a bomb attack took place between the Sennaya Ploshchad and the Technology Institute station in St Petersburg, killing 14 people and wounding 50.

Russian authorities say the DNA of Akbarjon Djalilov, the alleged bomber, has been matched to a bomb left at a second metro station.