NORTH SYDNEY, N.S. - About 170 passengers were stuck on a ferry off the coast of Cape Breton for a second day Wednesday as a Canadian Coast Guard icebreaker steamed toward the area to try to free it.

The Louis St. Laurent diverted from icebreaking duties off Quebec City to head toward North Sydney, N.S., where a Marine Atlantic ferry was idling offshore.

Thick ice and gusting winds were preventing the passenger ferry from getting into the ice-clogged port, said Tara Laing, a Marine Atlantic spokeswoman.

"What we really need at this point in time is for the winds to change direction to take the pressure off the ice,'' she said.

The ferry Caribou left Port aux Basques, N.L., early Tuesday and ran into problems just a few kilometres offshore from Cape Breton.

Mike Bonin of the coast guard said the St. Laurent came from Quebec because other icebreakers were tied up on other missions and is better suited to the task because it's the heaviest in their fleet.

Another icebreaker, Sir William Alexander, was near northwest Cape Breton and headed to the area after being called to assist, but had mechanical problems.

Bonin said the St. Laurent is expected to arrive on site sometime Thursday morning.

Laing said another passenger ferry, the Leif Ericson, was finally able to leave Cape Breton on Wednesday after arriving in port Monday.

It wasn't able to unload cars because the wharf it docked at did not have the necessary equipment.