LYONS, Colo. (AP) — With rain still falling and the flood threat still real, authorities called on thousands more people in the inundated city of Boulder and a mountain hamlet to evacuate as nearby creeks rose to dangerous levels.

The late-night reports from Boulder and the village of Eldorado Springs came as rescuers struggled to reach dozens of people cut off by flooding in Colorado mountain communities, while residents in the Denver area and other downstream communities were warned to stay off flooded streets.

The towns of Lyons, Jamestown and others in the Rocky Mountain foothills have been isolated by flooding and without power or telephone since rain hanging over the region all week intensified late Wednesday and early Thursday.

At least three people were killed and another was missing, and numerous people were forced to seek shelter up and down Colorado’s populated Front Range.

Late Thursday night, Boulder city officials said they sent a notice to head to higher ground to about 4,000 people living along Boulder Creek around the mouth of Boulder Canyon after 11 p.m. MDT, according to a report in Boulder’s Daily Camera newspaper.

Boulder County spokesman James Burrus told The Associated Press that about 8,000 telephone numbers with the message to evacuate were called, but officials aren’t sure how many individuals that represented.

The alert was prompted by rapidly rising creek levels caused by water backing up at the mouth of the canyon because of debris and mud coming off the mountainsides, the city Office of Emergency Management said.

Early today, Burrus said the entire hamlet of Eldorado Springs, about 500 people, was urged to evacuate because of a flash flood and mudslide threat along South Boulder Creek.

In Lyons, residents took shelter on higher ground, including some at an elementary school. Although everyone was believed to be safe, the deluge was expected to continue into today.

“There’s no way out of town. There’s no way into town. So, basically, now we’re just on an island,” said Jason Stillman, 37, who was forced with his fiancee to evacuate their home in Lyons at about 3 a.m. after a nearby river began to overflow into the street.

Stillman, who sought shelter at a friend’s house on higher ground, went back to his neighborhood in the afternoon and saw how fast-moving water had overturned cars and swept away homes at a nearby trailer park.