Law enforcement agencies on Wednesday night struggled to maintain order in parts of Los Angeles after the Dodgers won the World Series and boisterous fans began celebrating.

Unruly fans prompted police to declare an unlawful assembly in downtown L.A. Crowds in East Los Angeles gathered on Whittier Boulevard, with drivers of cars, pickups and motorcycles performing burnouts — prompting another unlawful assembly order there.

Businesses were looted near L.A. Live, including a Nike store, with multiple suspects arrested. Fogo de Chao Brazilian Steakhouse in downtown L.A. was tagged. Fireworks and projectiles were tossed at police officers, they said. A Metro bus was ignited and burned to its frame after vandals sprayed graffiti all over it near Echo Park Avenue and Sunset Boulevard.

“Metro is disappointed and angered by the senseless act of vandalism on one of our buses following the Dodgers’ World Series win,” Metro spokesman Dave Sotero said in an email. “We are thankful that the bus operator and the five passengers were safely evacuated before the bus was set on fire.”

Los Angeles police made 12 arrests tied to the celebration, Officer David Cuellar, a spokesman for the Los Angeles Police Department, said Thursday. Six were on suspicion of commercial burglary, four for receiving stolen property and two for failure to disperse.

In addition, sheriff’s deputies arrested two people after a rock hit a sergeant’s helmet and a firework ignited another deputy’s vest, officials said.

On Whittier Boulevard, drivers cruised between the 710 and 605 freeways to celebrate as fireworks were set off and some vehicles did burnouts, CBS Channel 2 reported. At one point, the road appeared to be partially blocked by fans near the Commerce Center as deputies monitored the situation.

Los Angeles police declared an unlawful assembly around 9:35 p.m. at Olympic Boulevard and Figueroa Street after fireworks went off near officers. Five minutes later, another unlawful assembly was declared in front of Dodger Stadium, where police issued a dispersal order at Sunset and Vin Scully Avenue.

LAPD continued to attempt to disperse celebrants as the night went on, issuing another dispersal order downtown at Flower and Ninth streets around 10:45 p.m.

Officers and deputies officers were outfitted with tactical gear including nonlethal weapons.

Deputies in East Los Angeles were seen shooting and throwing tear gas and smoke grenades as they ordered people to leave. Those remaining were threatened with arrest.

The LAPD declared a citywide tactical alert, allowing the agency to keep officers on duty beyond their normal shifts.

Staff writer Nathaniel Percy and City News Service contributed to this report.