Australian Twitter user reportedly urged Texas contest attack

An Australian Twitter user and supporter of the Islamic State group urged an attack on a Prophet Mohammed cartoon contest in Texas just days before two gunmen attacked the venue and were shot dead by police, it's been reported.

The Melbourne man, known only as "Australi Witness", last week shared a map of the community centre where the event was held while supporting calls for "brothers in Texas" to go there "with your weapons, bombs or with knifes", News Corp reported on Tuesday.

He also posted addresses of synagogues in Australia and the location of Anzac Day services.

"Kuffar (disbelievers) are holding a large Draw Muhammed (PBUH) event in Garland, Texas on May 3rd. Please spread to US brothers," Australi Witness posted.

Police shot dead two gunmen after they opened fire on a security guard outside the cartoon contest in a suburb of Dallas on Sunday night.

The right-wing American Freedom Defence Initiative (AFDI) organised the event that featured Dutch far-right politician Geert Wilders, who has been outspoken against Muslims.