Police are searching for a man who went missing while swimming in the Whanganui River.
Police said they were notified about 8.20am Friday that the shirtless man had failed to surface.
He had been seen swimming near Dublin Street Bridge.
"A rāhui is due to be placed over the Whanganui River from the walk bridge at Upokongaro to the mouth of the Whanganui River at the sea at 9pm tonight," police said in a statement.
"Iwi ask that locals refrain from recreational activity and food gathering over a three-day period.
"Search activities on the river will continue as Police work to locate the man and the Police National Dive Squad will be attending tomorrow."
Anyone with information was asked to call police on 105 and reference the event number P059047243.