The Greek Theatre, a major concert venue in the Griffith Park area of Los Angeles, was evacuated Sunday night. Yousef Erakat, better known as fouseyTUBE, was performing when his show was moved outside to the venue’s parking lot.

A bomb threat forced about 1,500 people to leave the venue. A call to police indicated an explosive device was placed at the venue, but an investigation did not discover any such package.

The threat forced the cancellation of the show by performer and YouTube personality Fousey, titled Hate Dies, Love Arrives.

Afterward, Fousey posted on Instagram about not being able to get into his own event.

“We’re just being tested right now,” he said.

The Los Angeles Police Department said early indications are that it may be a case of “SWAT-ting,” a prank in which a caller reports a problem in hopes that law authorities deploy an emergency team to a site.

The incident is the third evacuation of a Griffith Park site in the last few weeks, and the second this weekend involving a bomb threat. A brush fire that scorched 25 acres caused one area evacuation, and on Saturday, a mysterious package left outside the Griffith Observatory caused that area and nearby hiking trails to be evacuated. The package was investigated and found not to be a threat, and after three hours, civilians were allowed to return to the Observatory.

The Greek Theatre is owned by the city of Los Angeles and is one of the oldest outdoor concert venues in the nation, with its first show dating to 1931.