A boat smuggling migrants to Greece slammed into rocks off the Turkish coast Saturday and capsized, killing at least 33 people, including five children, as the choppy Aegean Sea continued to claim asylum-seekers’ lives this month at an appalling pace, officials said.

Coast guard officials said they rescued 75 people from the 56-foot vessel but government officials said they suspected more were trapped inside the sunken vessel and the death toll was likely to rise. Video footage on the Turkish shoreline showed police walking among bodies of several dead as they washed ashore, among them a toddler lying on his back in navy blue clothing.

The International Organization for Migration says drowning deaths are running at four times the rate of 2015, when many thousands daily sought to enter the European Union via Turkey by reaching one of more than a dozen offshore Greek islands, particularly nearby Lesbos.

Saturday’s deaths take the drowning total for January above 250.

Meanwhile, dozens of masked men believed to belong to neo-Nazi gangs carried out a number of assaults on migrants in Stockholm overnight amid rising tension over immigration, Swedish police said on Saturday.

The police had beefed up their presence in the city centre, deploying anti-riot and helicopter units after learning that extremists were planning “aggression on unaccompanied migrant minors” in the city late Friday. Spokesman Towe Hagg said police had not received any complaints of assault.