Residents of Alexandria's Warwick Village mended their fences with the City Council last week by rolling up the chain-link barrier they had erected to keep out roving gangs of vandals, only to be told by the council that they could have their fence -- or something like it -- back again.

"I'm glad you took it down," Mayor Charles E. Beatley Jr. told several dozen area residents who came to a council meeting last week for the latest chapter in the Great Fence War. "We didn't react to well when you put it up, but it's 1,000 percent more convincing" when residents approach the council without the illegal fence erected.

Warwick Village is a community of townhouses in the Del Ray area of Alexandria, near Glebe Road and Mount Vernon Avenue. Residents erected the fence between Sycamore and Landover streets with $400 of their own money last August after being unable to control gangs of vandals they say have terrorized residents, destroyed property and, in one case, extorted toys and presents from a homeowner in return for promising not to harass the resident.

But the fence, according to city codes, was as illegal as the vandalism it was meant to combat. By erecting it, city officials maintained, the residents had, in effect, seized city property.

"Well, the action was nonviolent," council member Carlyle C. Ring Jr. said last week when told the fence had come down.

However, nonviolent lawbreaking is still not the way the city fathers like to do business. On a motion by Vice Mayor Robert L. Calhoun, seconded by Ring, the council unanimously voted to "secure the valley against unwarranted trespass" for the next three months, until the city staff can figure out a way to erect a permanent fence or arrange an agreement for the alley's maintenance with local civic association members.

The action means the city may unroll the chain-link fence that formerly spanned the alley in three sections. One resident said city workers could easily find the fence. "it's in one of the neighbor's basement," she said.

The second public hearing on he subject prompted 13-year-old David Blair, who lives in Warwick Village, to complain that leaving the fence up would block a "neat" passageway to Mount Vernon Avenue for him and his pals.

Dispite his protests, the council sided with the voting-age adults and ordered the fence, or something that does the same type of defensive job, put up.