Security was tight as mourners gathered at a Jehovah's Witnesses Kingdom Hall for a memorial for megastar Prince, who worshipped there before he died last month.

Traffic cones lined the streets in front of the church in the Minneapolis suburb of Minnetonka, and media and fans were kept well back from Sunday evening's invitation-only event. City spokeswoman Kari Spreeman says police prepared for up to 500 guests, including up to 50 high-profile people.

Prince was known at the church as "Brother Nelson."

His two ex-wives held a star-studded memorial in Los Angeles on Wednesday night.

Prince was found dead at age 57 in his Paisley Park recording complex in Chanhassen on April 21. Authorities are still investigating.