- Vladimir Putin says Ukraine carried out the Crimea bridge attack.
- The Russian president described the explosion as an "act of terrorism."
- Russia says rail traffic across the bridge is running on schedule.
- The bridge across Kerch Strait is vital to supplying Russian troops.
Russian President Vladimir Putin on Sunday accused Ukraine of orchestrating the powerful blast that damaged a bridge linking Russia and Crimea, describing the explosion as an "act of terrorism."
"There is no doubt. This is an act of terrorism aimed at destroying critically important civilian infrastructure," Putin said in a video on the Kremlin's Telegram channel.
"This was devised, carried out and ordered by the Ukrainian special services," Putin said.
He was meeting Alexander Bastrykin, the head of Russia's Investigative Committee, who was presenting findings of an inquiry into Saturday's explosion and fire on the bridge.
The blast on the bridge over the Kerch Strait, a key supply route for Moscow's forces in southern Ukraine, had prompted gleeful messages from Ukrainian officials on Saturday but no claim of responsibility.
The bridge is also a major artery for the port of Sevastopol, where the Russian Black Sea fleet is based.
The damage to the bridge, which had been an imposing symbol of Russia's annexation of the Crimean peninsula, came amid battlefield defeats for Russia, and could further cloud Kremlin reassurances that the conflict is going to plan.
Rail services and partial road traffic resumed a day after the blast. Images showed half of a section of the bridge's roadway blown away, with the other half still attached.
Russia seized Crimea from Ukraine in 2014 and the 19-km (12-mile) bridge linking the region to its transport network was opened with great fanfare four years later by Putin.
Russian Deputy Prime Minister Marat Khusnullin said divers would start work on Sunday examining damage to the Crimea Bridge, with a more detailed survey above the waterline expected to be complete by day's end, domestic news agencies reported.
Russia's transport ministry said freight trains and long-distance passenger trains across the bridge were running according to schedule on Sunday. Limited road traffic resumed on Saturday around 10 hours after the blast.
"The situation is manageable — it's unpleasant, but not fatal," Crimea's Russian governor, Sergei Aksyonov, told reporters. "Of course, emotions have been triggered and there is a healthy desire to seek revenge."