Rihanna (file photo)

U.S. pop singer Rihanna has canceled a sold-out concert in Indonesia because of security concerns.

Event organizers said the 20-year-old singer was scheduled to perform Friday, before a crowd of 6,000 in the Indonesian capital, Jakarta.

Rihanna reportedly decided to cancel the performance while in Australia, one of several countries issuing travel warnings for Indonesia.

Indonesian authorities have increased security across the country since Sunday's executions of three Islamic militants convicted in the 2002 Bali bombings. Supporters of the bombers have threatened retaliatory attacks.

Two-hundred-and-two people were killed in the bombings on the island of Bali, including 88 Australians. It was Indonesia's worst terrorist attack.

A native of Barbados, Rihanna has achieved success in the United States and internationally with several hit songs, including the 2007 song "Umbrella."

Some information for this report was provided by AP and Reuters.