Sat Apr 11, 2015 10:26pm BST

Residents of a small northern Illinois town slammed by a powerful tornado were allowed to return to their homes on Saturday to assess damage but safety concerns prevented them from staying for long, officials said.

Two people were killed and 20 others injured when a rare EF-4 tornado, the second highest intensity, tore through Fairdale, about 75 miles west of Chicago on Thursday. It damaged or destroyed almost every structure in the town of about 200 people, local officials said.

Buses took evacuated residents on Saturday to assess damage and begin filing insurance claims, said a spokeswoman with the DeKalb County Sheriff's Office. All residents would be escorted out of the area later on Saturday, officials said.

"LP (propane) tanks are strewn about the village and some are leaking. Debris is hanging from trees and buildings that could cause death or serious injury," DeKalb County officials said in a news update on Friday.

"Power has been turned off until the search and rescue effort is complete," the statement added.

The DeKalb County Coroner’s office said on Friday two people, Jacklyn Klosa, 69, and Geraldine Schultz, 67, were killed in their homes.

Nobody was reported missing, officials said.

The tornado was one of several twisters that storm spotters reported in DeKalb and Ogle counties when a dangerous storm system rolled through the Midwest on Thursday evening.

Governor Bruce Rauner declared both counties disaster areas.

A few miles southwest of Fairdale, damage was also reported in and around Rochelle, where crews rescued people from the basement of a restaurant, officials said.

The tornado that hit Fairdale was at least an EF-4, storms characterized by winds of 166 to 200 miles per hour, said meteorologist Patrick Marsh of the National Weather Service Storm Prediction Center.

Two EF-4 tornadoes struck Illinois on Nov. 17, 2013, Marsh said, killing six people in the state and causing severe damage to the town of Washington.