United Nations, June 12: UN chief Antonio Guterres has condemned the attack on a Palau-flagged tanker off the coast of Oman in which three Indian seafarers have been killed, his spokesperson said. On Wednesday, the US struck another Palau-flagged tanker, MT Settebello, killing three out of the 24 Indian sailors on board. "...Notably, the Settebello tanker was hit and a number of Indian seafarers were killed.