LOS ANGELES (Reuters) - The San Diego office of California congressional candidate Carl DeMaio, one of three openly gay Republicans vying for Congress in 2014, were vandalized this week, just days before the primary election, his campaign said.

Staffers arrived at the campaign office on Wednesday morning to find cables and phone lines cut, water poured into computers and a printer and monitor smashed, according to a statement released by the campaign.

Police were called, but no suspects had been identified in the vandalism and no motive established, campaign spokesman Dave McCulloch said.

"We're not going to speculate on who or what or why, we've got a campaign to run and Tuesday is a big day for us," McCulloch said.

"We're more concerned with getting Carl's positive message reform out there," he said. "While our phones were down and Internet was down, instead of having our volunteers make phone calls we sent them out to walk the streets of Poway."

DeMaio tweeted a photo of smiling staffers working the phones in the office on Wednesday evening, along with the message: "This morning, our campaign office was highly vandalized. But we're back - and won't miss a beat."

A San Diego Police Department spokesman could not immediately be reached for comment on the investigation

DeMaio, a businessman, is seeking the Republican nomination to run against incumbent Democrat Scott Peters in November's general election.

(Reporting by Dan Whitcomb; Editing by Leslie Adler)