Two tankers catch fire off Romania’s coast amid a wave of deadly drone attacks on Black Sea shipping. More than half a dozen sailors are missing.

Rescuers are searching for seven sailors missing after a fire aboard the Wine Trader, a tanker flagged under San Marino, in Romania’s territorial waters in the Black Sea. The incident occurred around 7 a.m. on October 15, leaving four crew members rescued and seven still unaccounted for. In a separate incident on the same night, a chemical tanker named Yara J, flying the Comoros flag, also caught fire in the Black Sea.

The Yara J's crew successfully extinguished the fire without any casualties. Both ships were anchored off Romania’s coast when the fires erupted.

While local authorities have not yet connected these fires to a Russian drone attack, Reuters is reporting that at least five other cargo ships have faced drone attacks off the coasts of Romania and Bulgaria within the past 10 days. These attacks have all taken place outside NATO territorial waters and resulted in the loss of 23 sailors.