CORNWALL, Ont. -- More than 230 city workers, including paramedics, are on strike in Cornwall, Ont.

City officials say the strike began at 6 a.m. Thursday and also includes outside and library workers.

Their union, the Canadian Union of Public Employees, says the workers set up picket lines after contract talks reached an impasse.

About 150 inside workers, also represented by CUPE, have a strike deadline of 12:01 a.m. next Wednesday.

Paramedics' right to strike is partially limited by an essential services agreement.

The city is urging only patients with urgent health issues to call for an ambulance because the number of ambulances available will be reduced from the usual nine during the day and six at night.

It says three ambulances staffed by union employees will respond to urgent calls during the day, while two union-staffed ambulances will be available overnight.

"We have reached out to our partners, including area hospitals, fire services, police and taxi companies to ask for their assistance in responding to non-emergency calls during the strike," said paramedic services chief Bill Lister.

"We hope this will allow us to focus on emergency calls only," Lister said.

CUPE spokeswoman Alison Denis said the city made what it called a "final offer" on Tuesday.

"Whatever they choose to call it, it contained all the same problems that yielded a 93 per cent strike vote two months ago," Denis said.