As negotiations over a strike by 45,000 Verizon workers continued to sour, several thousand Washington-area customers experienced service outages caused by what the company called acts of sabotage.

Verizon reported 28 incidents of cut cables and damaged terminals in the District and Maryland since the strike began Sunday, out of more than 100 similiar incidents along the East Coast. Most of the vandalism has taken place in New Jersey and New York, Verizon spokesman Harry Mitchell said Friday.

Employees who work on the company’s wireline systems and in its call centers — about a third of the workforce — went on strike when their contract expired Sunday. Negotiations over a new labor agreement bogged down over disagreements about pensions and health-care benefits.

Aaron Dom, the area manager for Maryland and the District, said there has been a marked rise in serious vandalism on the company’s systems since the strike began.

“Normally, in a year’s time we’d see maybe six acts of sabotage,” he said, adding that of the 28 incidents of damage, 18 took place in the District and 10 in Maryland.

Vandals in the region appear to be cutting fiber-optic and copper lines as well as going after the large, square terminals on street corners, in what appear to be attempts to damage more of the system at a time, Dom said.

Verizon is offering up to $50,000 to anyone who can identify the vandals.

Mitchell would not say whether Verizon thinks striking workers are responsible for the sabotage but said it’s a “strong coincidence that these [incidents] started around the time when the union walked away from the table and went on strike.”

The Communications Workers of America and the International Brotherhood of Electrical Workers, which represent the workers, said they do not condone any illegal or violent actions and are confident that the picketers are respecting and obeying the law.

On Friday, the CWA said it filed unfair labor practice charges against Verizon Communications with the National Labor Relations Board offices in New York and Baltimore, charging that Verizon has not bargained in good faith. The company has obtained injunctions that prevent intimidation and illegal blocking of facilities by strikers in Delaware, New York and Pennsylvania, and has asked for injunctions in Massachusetts and New Jersey.

Management teams are dealing with the service outages, which, according to the FBI, have affected communications systems necessary for hospitals and police departments.

The FBI’s Newark Division confirmed that it “is looking at this matter from a security standpoint,” said Michael Ward, special agent in charge. “We are not taking sides in the strike; our concern is the security of critical infrastructure.”

Discussions continue between the unions and the telecommunications giant, but both sides accuse the other of not negotiating seriously.

CWA spokeswoman Candice Johnson said Verizon is using the allegations of sabotage to distract from these issues. “Forty-five thousand workers are being pushed out of the middle class by this company that wants to cut $1 billion in concessions. They would rather talk about anything than that,” she said.

The unions have also said that about 30 picketers have been hit by cars driven by Verizon management and replacement workers in several states, including a few in the D.C. area. Verizon spokeswoman Sandy Arnette said the company has checked into the claims with police departments and found the majority of the incidents were not serious.

The Montgomery County Police Department confirmed two reports of attempts to hit strikers with cars in Silver Spring. In both cases, the victims declined to be taken to the hospital. Johnson said three strikers involved in an incident Friday morning went to the hospital on their own.

Dom said he expects that local outages reported during the strike will be restored by the end of the weekend.