Island police are looking into the possibility that a brawl involving off-duty National guardsmen on the night of May 10 at the Atlantic Connection in Oak Bluffs is connected to the vandalism of National Guard trucks three nights later in Tisbury.

The windows on a half-dozen military trucks were smashed sometime Sunday night or early Monday morning, according to Tisbury police who are investigating the vandalism, which took place in the parking lot at R.M. Packer fuel company.

Police won't say whether the bar fight last Thursday can be linked to the vandalism. They would acknowledge only that it's possible. "It is plausible," said Oak Bluffs police chief Joseph Carter, a colonel in the National Guard who helped to bring the troops, 21 in all, to the Vineyard last week to build a ropes course near the airport for Island youth.

Tisbury police chief John McCarthy said only that his department is "looking into any aspect of any involvement" in the vandalism.

The fight at the Atlantic Connection started at around midnight during a reggae concert, according to one eyewitness who asked to remain unnamed. Police were not called to the club and only learned of the incident an hour after it happened.

The next day, Friday, Oak Bluffs police investigated an allegation that one of the off-duty guardsmen had used a chair to hit another bar patron.

"We took that very seriously and made an attempt with the alleged witness to identify that soldier," said Chief Carter. The witness could not identify any suspects and no arrests were made, according to police.

Chief Carter said he would prefer that bar owners call police as soon as an altercation starts, but Atlantic Connection owner Mike Santoro told the Gazette that the fight was a minor scuffle. "By the time we got to it, it had already fizzled," he said.

The eyewitness, however, described the fight between National Guard troops and other concert goers as "brutal."

"The National Guard guys were going crazy," he said. "And it went on uninterrupted. There were tables broken down and broken bottles. There were people hurt big-time. It was the biggest fight I've seen on Circuit avenue in years."

Chief Carter would not say whether police checked hospital emergency room records for potential victims of the fight. He said only that the investigation was "thorough."

Police remained more focused on the vandalism. Chief McCarthy estimated damages to the military vehicles at between $1,000 and $2,000. All but one of the trucks were damaged in the spree. Also, some equipment was stolen from one of the trucks, according to police.

"It really perturbs me," Chief Carter said. "They came here to work on a community project that saved the Island thousands of dollars, something to benefit our youth. They did a phenomenal job in a short period of time." The ropes course is set to open in late June.

Police are asking that anyone with information about who vandalized the trucks contact Tisbury police at 508-696-4240.