The Diamonds star was slated to kick off her Anti trek in San Diego, California on 26 February (16), but now that date, as well as her first eight stops throughout the U.S., have been shifted from February and March to May (16).

A representative for Rihanna tells The Los Angeles Times that "production delays" were the cause for the postponement.

The news comes days after she pulled out of a planned performance at Monday's (15Feb16) Grammy Awards at the last minute, citing vocal issues.

Nearly an hour and a half into the ceremony, Rihanna's spokesperson released a statement to Entertainment Weekly that read: "Based on Rihanna's examination after Grammy rehearsal today, Rihanna's doctor put her on vocal rest for 48 hours because she was at risk of hemorrhaging her vocal cords.

"The antibiotics she has been on for three days did not kill the infection adequately, therefore she cannot perform safely."

The Anti world tour, in support of her eighth studio album of the same name, is Rihanna's first solo trek since 2013. Her rumoured boyfriend, rapper Travis Scott, will serve as her opening act on the North American leg, while Big Sean and The Weeknd will join her for shows in Europe.