Hastings resident George Araia was fishing with a friend at the mouth of the river and beach all day and was one of the last people to see the missing woman.
From his fishing spot he saw the two children playing and believed the missing woman walked across the beach past him and a companion.
He did not realise anything was wrong until he heard emergency sirens later and heard about the children getting into trouble.
Araia said he spent the afternoon helping in the search for the woman and said the children were found about half an hour apart.
Several members of the public helped emergency services search for the woman while others watched from the beach. Photo / Warren Buckland
They were taken to Hawke's Bay Hospital and both were in a stable condition last night. Emergency services were first notified of the incident about 4.50pm.
A large crowd gathered on the Hawke's Bay beach yesterday evening to watch the incident unfold as a rescue helicopter flew overhead.
Searchers entered the murky river mouth and fanned out in a bid to find the missing woman, probing the water on their hands and knees.
An area up 500m from the shoreline was covered by the searchers.
Water Safety New Zealand chief executive Jonty Mills was aware of the incident and said drowning numbers were down over the holiday break.
"One preventable drowning is one too many, but unofficially over the break from December 22 to January 3 there were only four drownings," he said.
Water Safety New Zealand figures show 86 provisional drownings were recorded last year. Seven of those were children under the age of 5.
Searchers look for a woman who went missing after rescuing children in the Clive Rivermouth estuary. Photo / Warren Buckland
Mills said there had been improvements in some areas but the pre-schooler drowning statistic was particularly disappointing.
"Constant supervision is needed [with] children, it takes less than a minute for children to drown."
An Auckland Council water safety organisation says it's important for people to think before diving straight in to rescue someone in need.
Drowning Prevention Auckland chief executive Davin Bray said the loss of a loved one in an attempted rescue came with a "massive social cost to whanau and community".
