Russian authorities have no doubt that the explosion on the Crimean bridge was a terrorist attack aimed at destroying Russia’s critical civilian infrastructure, President Vladimir Putin said on Sunday. He added that Ukrainian special services were behind the attack reports Russian news agency Tass.

"This is just as you’ve said, there is no doubt [about it]. This is a terrorist act aimed at destroying the critical civilian infrastructure of the Russian Federation. It was ordered, authored and carried out by the special services of Ukraine," the head of state said at a meeting with the head of the Investigative Committee of the Russian Federation Alexander Bastrykin.

The head of the Investigative Committee confirmed this, adding that citizens of Russia and foreign countries helped the Ukrainian special services in preparation of the attack.

On Saturday morning, a truck exploded on the Crimean Bridge, collapsing two eastbound parts of its road section and subsequently setting ablaze a train of fuel tanks on a separate, adjacent rail portion of the bridge. As a result of the blast, three people were killed. A government commission chaired by Russian Deputy Prime Minister Marat Khusnullin was set up after the incident. Rail traffic has been restored on the bridge, which was also partly reopened for buses and automobiles.

When opening the meeting Putin asked head of the Investigative Committee to report about the first results of investigation into the emergency.

Bastrykin said that the investigation team of forensic experts and explosives specialists arrived very quickly at the scene, inspected the scene in detail, made preliminary, well-founded conclusions.

"We opened a case under the second part of Article 205 "Terrorism", and this is confirmed by the data at the initial stage of the investigation. They interrogated a lot of eyewitnesses, started special expert studies, which have been mainly completed - this is an explosive, genetic, forensic examination. Relevant instructions were given to conduct operational-search activities to the agencies of the FSB, the Ministry of Internal Affairs of Russia," he said.