Russia launched a massive air attack on the Ukrainian port of Odesa for a second night in a row, which one Ukrainian official on Wednesday described as “hellish”, but authorities vowed not to be intimidated and to continue work to export grain.

The attack was “very powerful, truly massive”, Serhiy Bratchuk, spokesperson for the Odesa military administration, said in a voice message on his Telegram channel on Wednesday.

“It was a hellish night,” he said, adding that details on damage and casualties would come later.

The attacks on Odesa, one of Ukraine’s main ports for exporting grain, followed a pledge of retaliation by Russia after a blast on a bridge linking Russia to the Crimean Peninsula on Monday that Moscow blamed on Ukraine.

Shortly after the bridge was hit on Monday, Moscow withdrew from a year-old Black Sea grain agreement that allowed for the safe export of Ukraine’s grain, a move the UN said risked creating hunger around the world.

“(They) are trying to scare the whole world, especially those who want to work for the grain corridor ... Ukraine, Turkey and the UN,” said Bratchuk. “But I think that all normal, rational people will look and say: Odesa was not afraid, is not afraid and will not be afraid — we will work.”

Most of Ukraine was under air raid alerts on and off starting soon after midnight on Wednesday, with Russia striking other places.