Ukraine has opened up a new corridor for ships carrying grain and other cargo through the Black Sea. The move comes after Russia pulled out of a deal to allow safe passage for commercial vessels sailing to ports in southern Ukraine.

Officials in Kyiv announced the opening of the corridor last week. They say the first ship passed through on Wednesday. The Hong-Kong-flagged vessel had been stuck in the port of Odesa for more than a year. It is loaded with tens of thousands of tons of cargo.

Russia has not issued a comment about the corridor. However, it has warned that it would consider any ship bound for Ukraine a potential threat. Over the weekend, Russian forces fired warning shots at, and boarded, another commercial ship.

The Russian military has been focusing its fire on facilities that support the shipping operations. On Wednesday, it once again launched attacks on grain silos and warehouses in the Odesa region.

Ukrainian forces are trying to counter those threats. They have unveiled a drone, called Sea Baby, that is designed to attack maritime targets and infrastructure.

The state security service released a video showing the drone. The head of the service, Vasyl Maliuk, told CNN that Ukrainian forces used the weapon last month in a strike on a bridge connecting Russia and Crimea. He added that more attacks will follow.