A manager of a motel behind the cordon said he heard two gunshots about 9.45am, which he first thought were tyre sounds, before police arrived.
More than 20 police vehicles were at the cordon, he said.
The manager said he heard someone had been shot at shops near a motel.
Police have blocked streets in central Hamilton this morning as they investigate an incident.Another motel worker told the Herald they heard gunshots between 9.30am and 10am.
A nearby resident also said he heard gunfire, and police have told him to stay home.
A large police presence shut down Ulster St past Mill St Pak’nSave supermarket.
Traffic and pedestrians are being diverted.
A resident, who did not want to be named, said the road was home to a large number of emergency housing. A motel on Abbotsford St is now taped off.
Some residents could be seen being escorted by police to their houses.