The University Lutheran Church opened its doors to the homeless of Harvard Square. Last night with the approval of Cambridge Mayor Alfred F. Vellucci, although it is in violation of city zoning and health regulations.

At 10 p.m. the 66 Winthrop St. Church located one block from four River houses began to sign in about five people seeking shelter from the pouring rain. More than five others followed during the course of the night.

"We may have to turn some people," said Stewart Guernsey, the first year Divinity student directing the project, as a group of men walked into the church.

The shelter, a large room in the church's basement with 20 mattresses on the floor, offered hot soup and bread donated by Savenor's Kirkland St. supermarket. A staff of seven volunteers were on hand to serve, including five from the Divinity School and one from the College.

Many of the homeless who came to University Lutheran last night said they heard about the shelter through the Thursday night dinner program at Christ Church on Garden St.

"I'd be out in the rain if the shelter wasn't here," said Raymond G. Villanueve, who described himself as a travelling artist.

"I'd probably be in a subway station if I wasn't here," said 19-year -old Michael B. Smith. Smith said he had been living at foster homes since he was seven.

"It feels good to be so near to Harvard," Smith said. "It's a good thing for the students because they can see how people live like this and study what kind of lifestyle street people base."

"I might be at the Harvard Science Center that they warned me off the property," said Peter Heimeyer, who said he is between lodging houses.

"I think it is amazing how people have responded and have given freely without our asking," said Constance A. Hammond, a first-year Divinity students who is coordinator for volunteers for the project. "It really is the loaves and fishes."

City officials Tuesday refused to grant the shelter a permit, arguing that it violates a variety of city ordinances. But Turner C. Graybill, a Boston attorney working at no pay for the church, argued yesterday that as a religious organization University Lutheran is exempt from these regulations.

And in an interview yesterday afternoon. Vellucci said he had decided not to take any action against the church. "If Pastor Reisz is going to open his doors to the homeless, then I'm going to have to be on his side. There were no by-laws when God created the world, no Cambridge or Harvard University," said the mayor.

Vellucci added that city officials had thought the shelter was a Divinity school project, not one directed by the churches.

A group of Harvard Square ministers, Guernsey, and Graybill were originally scheduled to meet yesterday morning with Vellucci and other city officials, who failed to show up.

"We left [Vellucci] a note saying that we trusted we had his support and decided to go ahead tonight," Graybill said yesterday.

In addition, they left a resolution from the Community Service Area Advisory Board, an official city panel, calling on the city "to make every effort in assist, approve, and coordinate the emergency shelter arrangements that have been improvised at the University Lutheran Church."