EL MONTE - Four men and a teenage boy were arrested Saturday while trying to break into a warehouse, where someone was running what police called the largest marijuana cultivation operation in El Monte history.

The suspects "all had gloves and clippers," said El Monte police detective Ralph Batres. "They also had a U-Haul truck. They were there to rip it off.'

Authorities received a call earlier today reporting that people were trying to break into a warehouse at 2520 Continental Ave. The location borders El Monte, which has its own police department, and South El Monte, which is patrolled by the Los Angeles County Sheriff's Department.

Deputies arrived first and called in the El Monte Police Department. The suspects were arrested about 11:30 a.m., authorities said.

"One of the guys (suspects) said there was a marijuana operations inside," Batres said.

El Monte police detectives got a search warrant for the warehouse and found about 3,000 growing plants, with a street value of about $1 million, Batres said in a statement headlined, "El Monte PD uncovers largest marijuana grow in El Monte history."

Benjamin Kwok, 37, of San Gabriel, Xing Xi He, 24, of Baldwin Park, Louie Frank Fraijo, 28, also of Baldwin Park, Raymond Guan, 29, of Rosemead and a 17-year-old boy from San Gabriel were all arrested and booked for commercial burglary, police said.

Who operated the indoor pot farm was not immediately determined.