Environment Canada has confirmed an F1 tornado touched down in Essex County in southwestern Ontario early Sunday morning.

Tornadoes are ranked on the Fujita scale, with F0 being the lowest and F5 the highest. An F1 tornado carries winds up to 180 km/h, which can uproot trees and overturn cars, evidence of which could be seen all over Leamington, Ont., after the twister touched.

On Monday, the town of approximately 30,000 residents on Lake Erie remained under a state of emergency.

Falling trees crushed cars and landed on houses, causing at least 13 homes to be condemned, but town officials expected that number to climb.

Mayor John Adams estimated damages in the millions of dollars, and said the town will appeal to the provincial government for emergency aid.

"[A] damage path length of about two kilometres in the area, and some of that path length looks like tornado damage, and some of it looks like straight-line wind damage," said David Rogers from Environment Canada.

No serious injuries

The tornado hit in the middle of the night, so no one got a good look at the twister, but seeing the damage in daylight, residents told CBC News they were shocked and relieved no one was hurt or killed.

There were some moments of concern for the parents of 45 boy scouts camping in tents and cabins at Point Pelee National Park's Camp Henry.

The park's superintendent, Marian Stranach, said staff had to reassure the families the children were safe, but that staff couldn't reach them because trees had fallen across the roadway.

"Right now the park is closed and we have no power and there are trees down along the road and we haven't had an opportunity to completely access the potential damage on trails and bridges and boardwalks, and we'd have to do all of that prior to opening the park," Stranach told CBC.

Despite downed trees and destroyed homes and vehicles, no one was injured when a tornado tore through Essex County, Ont., early Sunday morning. (CBC)

200-year-old trees uprooted

"There's a car buried under those trees there.… It's just amazing, the power," said Frank Meloche, who lives on Seacliff Drive in Leamington, one of the areas worst hit by the storm.

"We don't know whose chimney that is, but it's not ours," said Leah Meloche. Half of her roof was across the street, while the rest was in one of the trees that remained standing after the tornado.

Many trees, some an estimated 200 years old, were uprooted or torn in half. Some toppled over, crushing homes, while winds destroyed greenhouses, a major part of the town's industry and identity — Leamington is the Tomato Capital of Canada, known for its produce.

While the town will seek provincial help, Adams is more concerned in the short term with keeping curious crowds safely away from the storm's path.

"We are certainly trying to do it as peacefully as possible," said Adams.

"I understand and I was down there myself. And there are people who are actually moving the barricades, driving around them."

Power out for thousands

Thousands of homes were still without power Monday, and officials said it could be days before electricity is restored.

Just across Lake Erie near Toledo, Ohio, a tornado killed seven people several hours earlier. At least 50 homes were destroyed in a 100-metre-wide band that stretched about 16 kilometres southeast of the city.

Lyle Schulte searches for personal belongings in tornado debris in Millbury, Ohio, on Sunday. (Paul Sancya/Associated Press)

In Millbury, Ohio, the town's high school was destroyed the day before graduation ceremonies were to be held.

Jim Mazey, 35, was back Monday, searching for belongings of a friend whose house was destroyed. Six people had been in the home's living room when the tornado hit. Now, only the foundation is left. Two people in the house suffered serious injuries.

"I look at this and can't believe they lived," Mazey said.

At least four confirmed tornadoes hit northern Ohio over the weekend. The one that hit Milbury was the most powerful twister to hit Ohio in eight years.

The U.S. National Weather Service has rated it as an F3. A tornado that strong packs winds of 218 to 265 km/h.

Second tornado of year

Environment Canada confirmed Monday that another F1 tornado touched down Saturday afternoon in eastern Ontario near the Quebec border.

"Environment Canada investigators documented extensive damage to barns, grain bins, corn silos, houses and mobile homes, as well as countless broken and uprooted trees," said a posting on its website.

The affected area was near the town of Ste-Anne-de-Prescott.

Damage was confined to "a few properties," Linda Rozon, chief administrative officer of the township of East Hawkesbury, told CBC News. "A lot of trees were torn up," she said.

This tornado and the one in Leamington were Canada's first two twisters of the year, Environment Canada said.

With files from The Associated Press