Police want to speak to anyone who saw a man threatening a woman with a large knife in Wellington yesterday

It's alleged a 32-year old man wielding a knife threatened a woman known to him, who was also holding a small child, as well as damaging a bus shelter, in Khandallah's Cockayne Road yesterday.

Police were called to the scene where they tasered the man, who fell to the ground injuring his head.

He's in hospital in critical condition.

Anyone who witnessed the incident around midday yesterday is being asked to contact Police.