FAIRFIELD — A search and rescue operation is under way in the waters off Penfield Reef for two fishermen who went missing early Saturday morning.

Police Chief Gary MacNamara said the two men were part of a group of six fishermen who were fishing off the reef around 4 a.m. this morning. As the tide came back in, the men began to make their way back to shore, but only four made it back, MacNamara said.

Fairfield police and fire, and marine police from Bridgeport, Westport, and Stratford, along with the U.S. Coast Guard, are involved in the search, using both marine and air assets, MacNamara said.

“Long Island Sound can be very inviting at low tide, but it can turn very quickly,” MacNamara said.

In 1994, he said, a 17-year-old drowned off the reef when his waders filled up with water as the tide came in.

“This is what we believe may have happened here,” MacNamara said, but stressed around noontime, it was still very much a search and rescue operation.