FORT KENT, Maine - The raging St. John River spilled its banks, flooding more than 100 homes as emergency management officials feared the region could face its worst flooding in modern history Thursday.

©Shawn Patrick Ouellette / AP

A man walks his dog past flooded Main St. in Fort Kent, Maine, on Wednesday.

About 600 people were evacuated in the Fort Kent area, and the downtown became a ghost town. Blue lights flashed at most intersections as police, sheriff's deputies and the Border Patrol blocked off water-covered streets.

There were no reports of injuries.

At least 3 inches of rain combined with melting snow to raise the St. John to a record-setting 30 feet - about 5 feet above flood stage - causing water to begin rising on Main Street.

Officials were waiting overnight to see if the waters would spill over a levee that protects the downtown. The previous record crest of 27.3 feet was set in 1979.

"We have our fingers crossed that the river is going to hold steady at 30 feet. It's dangerously close to the top of the levee, but we hope that it doesn't get any higher," said Bruce Fitzgerald, spokesman for the Maine Emergency Management Agency.

Scientists described the flooding for the community of 4,200 people in Fort Kent as "greater than a 100-year event," said Lynette Miller, another agency spokeswoman.

Warnings issued in Canada

Across the river in Canada, warnings were being issued to residents in low-lying areas around Fredericton, New Brunswick, about 200 miles from Fort Kent. Up to 1,300 homes were threatened by rising water.

The river, the longest free-flowing river east of the Mississippi, totals about 410 miles in length, with 210 of those miles in Maine. It starts in Maine, forms the border with Canada at one section and continues on through New Brunswick to the ocean.

The International Bridge over the St. John between Fort Kent and Clair, New Brunswick, was closed amid fears that the raging waters could drag it down.

Maine Gov. John Baldacci, who flew from Augusta to get a firsthand look at the floodwaters, described the battered bridge as "ready to wash away." He sent a letter to the Federal Emergency Management Agency requesting disaster response and recovery assistance.

Baldacci said a church where he once attended a spaghetti supper was flooded along with other buildings and homes in the downtown area.

"Seeing that church and cars floating around in the back of it and seeing water splash up against the door of the credit union - it's all very hard to take," he said in a statement.

Evacuations, classes canceled

Evacuations also took place along the St. John River in Van Buren, downstream from Fort Kent, and in the Penobscot County town of Mattawamkeag, where the Mattawamkeag and Penobscot rivers were spilling over their banks, according to the National Weather Service.

Officials have been watching the St. John since last week, when rising waters caused concern on the Canadian side. Those waters had been receding until a deluge of at least 3 inches of rain began Tuesday, said Joseph Hewitt of the National Weather Service in Caribou.

There was still a half-foot of snow on the ground following a winter that dumped around 200 inches of snow in the region, and the melting snow exacerbated the situation.

Classes were canceled and students were moved from the University of Maine at Fort Kent to pave the way for a shelter, where a handful of people took up residence Wednesday night.

The Maine Warden Service and the Washburn fire and police departments directed more evacuations downstream from two dams in danger of breaching.