South Wales Police say the injury to the man involved in an incident in Taff Street, Pontypridd is not life threatening.
At 12.30pm, police and paramedics were called to the Tesco Express store where a 51 year-old man was in need of medical attention for a single puncture wound to his abdomen.
He was taken by air ambulance to the University Hospital of Wales where he is in a stable condition.
The circumstances surrounding this incident as yet are unknown and under investigation.
There were dramatic scenes in Pontypridd this afternoon. We understand people are shocked and there are rumours flying around the community. I urge people to remain calm and would like to assure them that we have a team of officers are trying to establish what happened. We will update them as soon as we know more about what we are dealing with.
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Fine and dry at first but becoming largely cloudy with outbreaks of rain or drizzle.
First Minister Carwyn Jones says Wales must not get a bad deal in Brexit negotiations. He was speaking at meeting of British-Irish Council.
Isolated showers may last into the late evening, but a dry night.