Few details were immediately disclosed about the warrant, which a spokesperson for U.S. Immigration and Customs Enforcement said was issued by a magistrate judge and "filed under seal in relation to an ongoing investigation."
"Because the warrant is under seal, we are not able to comment on the scope or nature of the investigation," said Virginia Kice, ICE's western regional communications director.
The investigation at the hotel-casino, located at Florence and Eastern avenues, was being conducted by members of the Los Angeles High-Intensity Financial Crime Area Task Force, which includes ICE's Homeland Security Investigations.
The IRS Criminal Investigation division, the California Bureau of Gambling Control and the U.S. Attorney's Office also participated in the raid.
"This is beyond belief," a concerned citizen told Eyewitness News. "The people are wonderful. The service is wonderful. You don't understand that 1,000 people are now out of their job. This is devastating to the community."
Homeland Security Investigations personnel were seen in the facility's parking lots, whose entrances were cordoned off by yellow tape and ICE vehicles at about 7 a.m. Officials said the casino would be closed the remainder of Tuesday.
The Bicycle Hotel & Casino told Eyewitness News in a written statement, "We are working with authorities and currently do not have additional information. As soon as the federal agents have completed their work, we will be in full operation."
Employees standing outside the casino said they were concerned about whether they would still have a job after Tuesday.
"Well as of right now, we're not sure," an employee told Eyewitness News. "We don't know what's going on so we'll find out tomorrow and we'll see if we're a bit more concerned tomorrow."