Residents of a city trailer park in Fort McMurray, Alta., were force to leave their homes, while others are on evacuation alert following days of heavy rain.

A state of emergency was declared in the Regional Municipality of Wood Buffalo on Tuesday after precipitation caused the Hangingstone River to overflow its banks, threatening nearby homes.

Ptarmigan Court Trailer Park, located near the waterways of Fort McMurray, was evacuated as emergency personnel went door-to-door enforcing a mandatory order. Residents in 275 homes are on evacuation alert.

鈥淎reas that have been identified as evacuation zones, especially those classified as mandatory, are not safe at this time,鈥 RCMP said in a statement. 鈥淎nyone who remains in those areas will likely find themselves with minimal resources.鈥

Volunteers have filled sandbags but there is nowhere to put them as flood waters are moving rapidly and riverbanks are too unstable.

Brad Grainger, Wood Buffalo鈥檚 deputy chief of operations, said Wednesday that the community is at 鈥渢he mercy of Mother Nature,鈥 as more rain is forecasted for the region.

A boil-water advisory is also in effect in some areas.

Mayor Melissa Blake said Wednesday residents are being told to stay away because of the crumbling riverbanks.

鈥淚t鈥檚 the first time I have seen these small rivers take on such an aggressive tone with the amount of water flows coming into the region, and it genuinely does provide a serious hazard for the folks that are near those banks,鈥 she said.

The communities of Waterways and Draper are under a boil-water advisory issued by Albert Health Services. Under the order, tap water must be boiled for at least one minute before it can be used for drinking, cooking, preparing foods, brushing teeth or making ice.

At Keyano College 鈥 which sits near the Hangingstone River in Fort McMurray -- water had already infiltrated the school's athletic facility.

Some evacuees were taken to a reception centre at the Frank Lacroix Arena in Beacon Hill, while others took shelter with friends or family in the area.

With a report from Jeff Harrington and files from The Canadian Press