At least 15 people died on Thursday after a boat carrying Rohingya refugees fleeing violence in Myanmar capsized in the seas off Bangladesh on Thursday, AFP reported. Witnesses and survivors said the vessel overturned close to the coast after hitting a submerged object and later washed ashore in two parts. The victims included 10 children and four women.

“They drowned before our eyes,” local shopkeeper Mohammad Sohel was quoted as saying by AFP. “Minutes later, the waves washed the bodies to the beach.”

The local police told the news agency that 14 bodies had been washed ashore so far, and that the number was likely to rise.

UN Secretary-General António Guterres asked Security Council members to consider taking “swift action” to prevent further instability in the region. “The situation has spiralled into the world’s fastest developing refugee emergency and a humanitarian and human rights nightmare,” Guterres said on Thursday.

Over the past few months, around 120 Rohingya refugees, many of them children, have drowned trying to reach Bangladesh in small fishing boats. More than 7 lakh Rohingya refugees are believed to be in Bangladesh, and 4.2 lakh of them have arrived in the past three-and-a-half weeks, according to the United Nations.