Efforts by Australia's National Rugby League to restart matches this month faced a fresh hurdle Thursday when a group of players refused to have compulsory flu vaccinations. The jabs are included in strict health protocols agreed by the league in return for clearance to resume the competition on May 28, despite ongoing social distancing restrictions imposed to curb the coronavirus epidemic. But the official nrl.com website reported Gold Coast's Bryce Cartwright and the Canberra Raiders trio of Sia Soliola, Josh Papalii and Joseph Tapine were refusing the injection. Canberra chief executive Don Furner said the Raiders trio were continuing to train while the club awaited further guidance from the NRL. "It's clearly new ground for all of us. This is not a normal year, it's anything but a normal year with some extraordinary circumstances that are coming up," he told the website. "But we are getting them back to training today and then we'll await further information and instruction from the NRL." The cash-strapped NRL suspended its season on March 24 due to Australia's coronavirus shutdown and has pushed hard to resume play so it can retain revenue from broadcasting rights. It plans to stage matches in Sydney, with the New Zealand Warriors based in rural New South Wales and the Melbourne Storm setting up camp on the NSW-Victoria border. But a string of lockdown breaches by high profile players has prompted warnings from authorities that the competition will not go ahead if the rules are not obeyed. Prime Minister Scott Morrison weighed into the vaccine row this week, saying he supported a policy of "no jab, no play". ns/dm/hg