CEBU -- Tourists flocked to a Philippine jail Saturday to watch about 1,500 inmates perform a special Michael Jackson dance tribute in honor of the dead star, officials said.

The jailbirds spawned a worldwide Internet hit two years ago with their morning exercise routine using synchronised movements based on the groundbreaking 1982 "Thriller" video.

An unusual number of visitors were signing in at the Cebu city provincial jail Saturday to watch the prisoners perform at 3:00 p.m. (0700 GMT) following the death of Jackson, 50, in Los Angeles on Thursday.

"Visitors have been calling and checking in with us for this afternoon's performance," said a prison official who did not want to be named.

An Agence France-Presse photographer at the jail said visitors were told to sign in hours ahead of the scheduled performance to guarantee a slot.

The prisoners' dance found its way onto the popular Internet video-sharing site YouTube, where it developed a huge fan base.

The four-minute video has so far generated more than 23 million hits.

The inmates in their saffron uniforms have themselves become tourist attractions, with visitors allowed to have their pictures taken with the dancers after each performance.

Choreographer Byron Garcia, a prison consultant and the brains behind the dance exercise, said he was shocked by Jackson's death and that many of his wards were grief-stricken.

"I am shocked, the inmates are still in grief after learning that their idol is already dead," Garcia told AFP.

He said the inmates had performed the routine for visiting tourism officials on Thursday afternoon, just hours before Jackson died.