Boaters heading to lower Lake Huron should avoid an area where a dredge sunk and tugboat capsized Thursday morning.

A 100-yard safety zone has been established in the area of the incident, and a 300-foot diesel sheen has been reported, according to a release from the U.S. Coast Guard.

"The Coast Guard will continue to ensure the safety of responders and the public," said Lt. Justin Westmiller, public affairs officer at Coast Guard Sector Detroit, in a release.  "Our other objectives are to initiate any appropriate actions to control the source and minimize further release, assess the trajectory of any hazardous materials in the water and identify any sensitive areas that need protecting, and keep the public informed as best we can."

The Coast Guard reported that the 110-foot dredge Arthur J. sank, and the 38-foot tugboat Madison capsized, about 4:35 a.m. Thursday. The incident occurred about five nautical miles north-northwest of the entrance to the St. Clair River, one nautical mile from the Michigan shoreline and four nautical miles from Canadian waters.

There were no injuries, and the Coast Guard is coordinating the cleanup with Michigan Pollution Control. The Michigan Department of Environmental Quality, the Environmental Protection Agency, Environment Canada and St. Clair County Emergency Management are operating out of command post at Coast Guard Station Port Huron.

A containment boom has been set up around the diesel spill, and the cause of the accident is being investigated.

Information about the incident is being broadcast to mariners in the area.

“This unfortunate incident demonstrates just how important the U.S. Coast Guard and our state and local first responders are to Michigan and the Great Lakes States," U.S. Rep. Candice Miller, R-Harrison Township, said in a release. "We can see how quickly and professionally they have responded to contain the diesel spill in Lake Huron and mitigate any possible damage done to our water.”