A tornado — multiple tornadoes, according to some reports — tore through Enid, Okla., Thursday, churning up earth, destroying about 40 homes, and injuring at least 10 people.

The aftermath of the violent storm resembled a bombed-out war zone.

The National Weather Service will determine the scale of the tornado, but meteorologists are unofficially rating it as EF-4 or EF-5. The ratings show the intensity of the storm — the higher the number, the more severe the tornado. For example, an EF-4 rating means a violent tornado with winds of 166 to 200 miles per hour. While such severe tornadoes make up less than 2 percent of all tornadoes, they cause about 70 percent of tornado-related deaths.

The tornado also ripped its way through Vance Air Force Base, forcing its closure. Only essential personnel are working at the base to restore power and water.

Authorities declared a tornado watch until 11 p.m., and severe weather is expected throughout the weekend. Local officials expressed relief that there were no fatalities but urged everyone to stay safe.

“I am very grateful to report that while homes have sustained significant damage, there have been no fatalities and only minor injuries sustained,” the mayor, David Mason, said.

“Cindy and I are praying for all Oklahomans in harm’s way tonight as severe storms, damaging winds, and tornadoes move across our state,” said Sen. James Lankford (R-Okla.).

Tornadoes also affected Iowa and Kansas, with 17 reports of tornadoes across all three states.