ZAPORIZHZHIA, Ukraine (AP) — Russia President Vladimir Putin on Sunday called the attack on the sprawling Kerch Bridge to Crimea “a terrorist act” carried out by Ukrainian special services and Russia’s investigative chief immediately opened a criminal terror investigation into the explosion that damaged a prominent Russian landmark.

What Russian authorities are calling a truck bomb on Saturday hit the huge bridge linking Russia with the Crimean Peninsula, which Moscow annexed eight years ago from Ukraine. Road and rail traffic on the bridge were temporarily halted, damaging an important supply route for the Kremlin’s forces and dealing a sharp blow to Russian prestige.

“There’s no doubt it was a terrorist act directed at the destruction of critically important civilian infrastructure of the Russian Federation,” Putin said in a video of a meeting Sunday with the chairman of Russia’s Investigative Committee, Alexander Bastrykin. “And the authors, perpetrators, and those who ordered it are the special services of Ukraine.”

Bastrykin said said Ukrainian special services and citizens of Russia and other countries took part in the attack.

“We have already established the route of the truck,” he said, adding that it had been to Bulgaria, Georgia, Armenia, North Ossetia and Krasnodar — a region in southern Russia — among other places.

The statements followed overnight Russian missile strikes on the city of Zaporizhzhia that brought down part of a large apartment building, leaving at least a dozen people dead.

The six missiles used in Sunday’s overnight attack were launched from Russian-occupied areas of the Zaporizhzhia region, the Ukrainian air force said. The region is one of four Russia claimed as its own this month, though its capital of the same name remains under Ukrainian control.

Russia has suffered a series of setbacks nearly eight months after invading Ukraine in a campaign many thought would be short-lived. In recent weeks, Ukrainian forces have staged a counteroffensive, retaking areas in the south and east, while Moscow’s decision to call up more troops has led to protests and an exodus of tens of thousands of Russians.

Recent fighting has focused on the regions just north of Crimea, including Zaporizhzhia. Ukrainian President Volodymyr Zelenskyy lamented the latest attack in a Telegram post.

“Again, Zaporizhzhia. Again, merciless attacks on civilians, targeting residential buildings, in the middle of the night,” he wrote. At least 19 people died in Russian missile strikes on apartment buildings in the city on Thursday.

“From the one who gave this order, to everyone who carried out this order: They will answer,” he added.

Ukrainian Foreign Minister Dmytro Kuleba called the attacks on civilians a war crime and urged an international investigation.

Stunned residents watched from behind police tape as emergency crews tried to reach the upper floors of a building that took a direct hit. A chasm at least 12 metres (40-feet) wide smoldered where apartments had once stood. In an adjacent apartment building, the missile barrage blew windows and doors out of their frames in a radius of hundreds of feet. At least 20 private homes and 50 apartment buildings were damaged, city council Secretary Anatoliy Kurtev said.

Regional police reported Sunday afternoon that 13 had been killed and more than 60 wounded, at least 10 of them children.