Russian President Vladimir Putin on Saturday ordered tighter security for the bridge from Russia to Crimea as well as the infrastructure supplying electricity and natural gas to the peninsula, Interfax said.
In a decree issued hours after the bridge was damaged by a blast, Putin said the FSB security service would be responsible for strengthening protection measures.
The blast on the bridge over the Kerch Strait, for which Russia did not immediately assign blame, prompted gleeful messages from Ukrainian officials but no claim of responsibility.
Russian officials said three people had been killed, probably the occupants of a car travelling near a truck that blew up.
Despite the damage, limited road traffic resumed about 10 hours after the blast, and the Transport Ministry cleared rail traffic to restart shortly afterwards.
Russia seized Crimea from Ukraine in 2014 and the 19-km (12-mile) Crimean Bridge linking it to Russia’s transport network was opened with great fanfare four years later by Putin.