Combs, 45, was freed from Los Angeles County jail after posting bail, several hours after his afternoon arrest, jail records showed.
He was arrested at UCLA's Acosta Athletic Training Complex on suspicion of assault with a deadly weapon -- a felony charge -- shortly after 12:30 p.m. local time, according to a statement from campus police.
UCLA campus police updated the charges late Monday night, adding two more counts of assault with a deadly weapon, one count of making terrorist threats and one count of battery.
The Los Angeles County Sheriff's Department initially listed his bail as $160,000 on its website -- although two officials inside the sheriff's department later said the amount was $50,000 -- and Combs was released at 9:50 p.m. after bail was posted. The reason for the discrepancy was not clear.
He is scheduled to appear in court July 13 at 8:30 a.m.
No one was seriously injured, and campus police are investigating. Officials did not identify the victim of the alleged assault or say what led to it, but said the incident was captured on video cameras inside the office of UCLA strength and conditioning coach Sal Alosi.
Fox Sports reported the alleged victim was Alosi, the former New York Jets staffer known for tripping a Miami Dolphins player near the Jets' sideline in a December 2010 game. Alosi was suspended indefinitely for the incident and resigned soon after.
One former Jet, speaking on the condition of anonymity, said he was "not shocked at all" by reports that Alosi may have triggered an alleged assault Monday by Combs by verbally accosting Combs'son at a strength and conditioning session.
Combs' son,Justin Combs, is a redshirt junior defensive back on the UCLA football team, which has been working out on campus. He has played in just a handful of games in his three years with the team.
Alosi "was riding Justin, screaming intensely at him," according to TMZ.com, which first reported the arrest.
"He did that with the Jets," the former Jet said of Alosi's in-your-face approach.
The son of another major rap star also plays football for the Bruins. Snoop Dogg's son, Cordell Broadus, is a wide receiver who signed with the team this year.
Football coach Jim Mora thanked his staff in a statement for their professionalism in handling the situation.
"This is an unfortunate incident for all parties involved," Mora said. "While UCPD continues to review this matter, we will let the legal process run its course and refrain from further comment at this time."
Sean Combs' representatives did not immediately respond to requests for details or comment.
It's the latest of several allegations of violence by Combs.
He was acquitted of bribery and weapons-related charges in connection with a 1999 shooting at a New York nightclub. A jury cleared Combs of firing a weapon during the dispute that wounded three bystanders, as well as bribing his chauffeur to take the rap.
Combs was arrested in 1999 for his involvement in the beating of former Interscope executive Steve Stoute in New York. Combs apologized, the charges were reduced and he was ordered to attend an anger-management class.
Combs and Stoute have since mended their relationship, appearing on stage together at Cannes in 2013.
Earlier this year, an Arizona man accused Combs of punching him in the face at a Super Bowl party. Combs was not arrested.
ESPNLosAngeles.com's Arash Markazi, ESPN.com Jets reporter Rich Cimini and The Associated Press contributed to this report.
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ESPN Pac-12 reporter Kevin Gemmell discusses Sean "Diddy" Combs' arrest for assault with a deadly weapon on the UCLA campus, where his son is on the football team.