The upper and middle reaches of the Whanganui River have been closed to kayakers and canoeists

The Department of Conservation made the decision after four paddlers tested positive for Covid-19 -- saying it has concerns for visitors and vulnerable rural communities.

Local Democracy Reporting says DOC has shut down the Whanganui Journey from the Ngahuinga entry point in Taumarunui to the exit at Pipiriki.

Operations manager Connie Norgate says the paddlers caught the virus after coming off the river at Pipiriki on Monday.

She says the journey will reopen after a deep clean and when it's safe to do so.

There were about 100 people on the river when it closed.