India has summoned the Russian ambassador to protest the killing of four Indian nationals in an attack on a commercial vessel off the coast of Ukraine. The Indian government confirmed that the MV Golden Leo came under attack while departing the port of Odesa on Sunday. The vessel had 17 crew members on board, including five Indian nationals. Four were killed, and one remains in critical condition. The Ministry of External Affairs told the Russian diplomat that the attack on the merchant vessel was unacceptable. The incident adds to tensions in the region as the conflict in Ukraine continues. An investigation is underway. The Indian government has not provided further details about the attack or the circumstances of the deaths.