The drownings of two children at a Perth park on New Year’s Eve have led to calls for an independent review after claims safety concerns about the venue were ignored.

A four-year-old girl and six-year-old boy died after they were found unconscious in the Swan River near where revellers had gathered for new year celebrations and close to a children’s playground.

The pair, from separate families, was spotted in the water at a popular family picnic spot in Burswood Park, three kilometres east of Perth, about 5.25pm on Sunday.

They were unresponsive when passersby pulled them from the river.

Despite the efforts of nine paramedics and doctors at Perth Children’s Hospital, the children could not be revived.

Western Australia Liberal leader Libby Mettam on Tuesday called on Police Minister Paul Papalia, who has oversight of the Burswood Park Board, to launch an independent review into the deaths.

The call came after claims safety concerns about the park raised with the board went without response, Mettam said.

“It is horrifying to learn that concerns have been raised and seemingly nothing done about them,” she said.

“There must be transparency about the government’s response, or lack of response, to any safety warnings.”

The West Australian newspaper reported that parents had pushed for a safer fenced area at the playground for as long as six years. The playground is fenced off, but none of its three entry gates has lockable latches, and all can be easily opened.

Mettam said any review must examine additional safety precautions for the park for any future large events close to the river.

“We obviously can’t fence the river. But where there are playground facilities like these so close to the water, we must ensure they are safe and secure.”

Police officers assigned to the Coronial Investigation Squad have taken carriage of the investigation.

Papalia’s office has been contacted for comment.

-with AAP