BISMARCK, N.D. (AP) — Two tornadoes that killed six people in North Dakota and New York each had wind speeds topping 100 mph and caused brief but widespread damage as they tore through largely rural areas, officials said.

Three people, all in their 70s and 80s, died in rural Enderlin, North Dakota, during a storm that struck late Friday and early Saturday, the Cass County Sheriff’s Office said. Three others, including twin 6-year-old sisters, died Sunday in a storm that struck the hamlet of Clark Mills in central New York, the Oneida County Sheriff’s Office said.

The National Weather Service gave preliminary ratings of EF-2 to EF-3 or potentially higher for three tornadoes that struck eastern North Dakota — meaning wind speeds of 111 to 135 mph and 136 to 165 mph, respectively, with varying severity of damage. EF-3 and stronger ranges are not usual for the Northern Plains, National Weather Service Meteorologist Jacob Spender said.

“As we go higher on the scale, it’s not as common but they can still happen,” he said.

The tornadoes uprooted numerous trees, tossed train cars and damaged houses, Spender said.

The night included supercells in southeastern North Dakota and a derecho — a powerful windstorm — that tore across the state to the east.