New Delhi, Jan 19 (IANS): Over 250 contractual workers and ambulance drivers of the Delhi government-run Centralised Accident and Trauma Services (CATS) went on a strike Monday against the government's decision to outsource the operation and maintenance of the vehicles.

As part of the strike, over 50 ambulances were not operated despite receiving calls from patients.

The Delhi government by its Jan 9 order invited bidders for operation and maintenance of CATS ambulances and control room.

"This is an extremely negative step. This should have been thought prior to the ambulance service inception," said Surinder, a member of the CATS workers' association.

"We had two meetings with the CATS director and were assured that the outsourcing won't happen. However, we know that the pressure is from the government and the director too is helpless," he told IANS.

The Delhi government is also in the process of procuring 110 more CATS ambulances. At present, there are 152 ambulances -- 21 advanced life support ambulances, 10 basic life support ambulances and 121 patient transporting ambulances.