ORONO, Maine — Multiple police agencies descended on a brand new apartment complex in Orono on Saturday and Sunday nights to break up parties that drew at least 300-400 people to a single parking lot. State police later said in a website posting that the party created “near riot conditions.”

The Grove, owned by North Carolina-based Campus Crest Communities Inc., opened this past weekend, welcoming its first batch of University of Maine students. The facility, located a half-mile from the Rangeley Road entrance to the university, has room for 620 tenants.

Just hours after The Grove residents began moving in, police were called to the area around Building 12 about 11 p.m. Saturday in response to a series of noise complaints made by other Grove tenants and residents on Park Street.

Police arrived to find between 300 and 400 men and women crowded together in the parking lot around Building 12, Orono police Capt. Josh Ewing said Tuesday afternoon.

Ewing said police arrived to find hundreds of people “drinking, yelling and listening to music.”

The Grove’s management wasn’t able to break up the crowd and “they wanted these people moved along and dispersed,” the captain said.

Orono police called in other officers from Old Town, Veazie, Hampden, Maine State Police and the Penobscot County Sheriff’s Office, “just because of the potential of having to arrest people and for our own safety,” Ewing said. In all, 20 police officers arrived and the crowd began to disperse after seeing the cruisers.

Police waited at the 21-apartment-building complex for a couple of hours after the party broke up to make sure people didn’t come back, Ewing said.

The scene was more chaotic — and more dangerous — when police were called back to the apartments after more noise complaints 24 hours later. Police arrived Sunday night to find an even larger, rowdier gathering, according to Ewing.

Attendees, many of whom recorded the scene with their smartphones and later posted videos and pictures to social media websites, urged people to jump from or skateboard off the entryway roof. People shouted, “Do it, do it,” as the jumpers weighed whether to take the leap.

“Our goal here is to ensure people’s safety,” Ewing said, “and when we see that many people together and some jumping off roofs … we need to mitigate that.”

The Orono police captain said he didn’t think the party was “near a riot.”

Again, about 20 officers from several police agencies arrived, but this time the crowd didn’t disperse on its own, Ewing said.

The captain took out his bullhorn and told the partygoers that if they didn’t leave the scene, then police would start making arrests. After the warning, people then began leaving, Ewing said.

A spokesman for the public relations firm that represents Campus Crest Communities said Wednesday that The Grove’s management and staff were taking the incidents seriously and that the complex planned to crack down.

“The safety and well-being of our residents is our top priority and concern,” Jason Chudoba said. “We have increased security presence, implemented stricter facility access controls and are coordinating with the Orono police and residents in order to maintain an extraordinary student lifestyle experience.”

“Residents who compromise the safety and security of The Grove community will not be tolerated,” Chudoba added.

Ewing said Veazie police made the only arrest in connection with the party.

After the bullhorn warning broke up Sunday’s party, which police said drew about 500 people to the parking lot, Veazie police Sgt. Keith Emery and two other officers, along with other groups of police from the responding departments, began walking the property and telling stragglers to go home.

Police spotted Robert Neal, 18, of Monmouth walking toward the center of the complex and asked him where he was going. Neal said he was going to meet some friends in a different building, according to the police report.

When Emery found out Neal wasn’t a resident of The Grove, the sergeant told him to go home. Neal “stood his ground and began to question the order,” according to Emery’s report, adding that the man was warned at least six times that he would be arrested if he didn’t leave.

Neal eventually agreed to leave and police moved on to check other areas of the complex.

The same group of officers eventually came upon a gathering of people near the pool in the middle of the complex. The officers spotted Neal in that group and asked him why he was still on the property. Neal told police he had tried to leave but was blocked by a gate or fence so he turned back, according to the police report.

Neal was arrested and charged with criminal trespass and failure to disperse, both Class E offenses.

“He stiffened up and was not cooperating,” but soon submitted to arrest, Emery said.

“While walking, he apologized over and over and admitted he had enough chances [to leave],” the sergeant said.

Police said they weren’t aware of any injuries resulting from the party, but did field reports of a dented car and a broken window in one of the apartments.

“I think there’s going to be a larger police presence for the foreseeable future so this doesn’t occur [again],” Ewing said, adding that police would be on the lookout for underage drinking and parties that might get out of hand.

A representative from The Grove did not return a call requesting comment Tuesday afternoon.