A paediatrics expert on Saturday said there's been no easing of the winter flu outbreak in Hong Kong, and he expects the situation to continue for several more weeks.

Professor Patrick Ip from the Department of Paediatrics at the University of Hong Kong said the number of influenza cases would usually fall off in April.

"The condition of the influenza outbreak [had] been persistent throughout May, and we are expecting actually even in June, there will still be a few more weeks of influenza outbreak affecting many of our young children," he said.

"So far, we find most of those severe influenza cases, including the death cases, occur more dominantly in young children, particularly with those without any influenza vaccination."

He urged parents to get their children vaccinated. Four children have died of flu so far this year.