CHESAPEAKE, W.Va. (AP) — Thunderstorms dumped heavy rains that caused significant flooding in parts of West Virginia on Monday, authorities said.

Gov. Jim Justice issued a state of emergency in at least five counties, enabling the National Guard to activate swift-water rescue teams and use helicopters in areas hit by significant flooding.

“This is an ongoing, life-threatening emergency,” the Kanawha County Commission said on social media. “Please seek higher ground.”

The commission said that based on radar estimates, up to 6 inches of rain fell in a short amount of time Monday in areas east of Charleston, sending several creeks out of their banks. Classes at several schools were canceled. Mudslides closed U.S. Route 60 in the Kanawha County community of Cedar Grove, and flooding led to lane closures on parts of Interstate 77.

Communities hit the hardest were along hillsides where runoff flowed into narrow valleys. The rains fell on top of ground saturated by previous severe storms over the weekend.