Wishaw Hospital houses one of three Lanarkshire casualty units

Patients were taken to Hairmyres and Monklands hospitals, which witnessed increases of 42% and 36%.

NHS Lanarkshire said three hospitals in the county were experiencing unprecedented patient levels.

Wishaw General Hospital accident and emergency was reopened to general admissions at 1430 GMT.

The hospital is in the constituency of First Minister Jack McConnell.

Officials said the hospitals were treating people who had "become quite ill" from the bug and needed urgent care.

Winter plans

A statement from NHS Lanarkshire said: "We are experiencing unprecedented levels of activity in the three NHS Lanarkshire Hospitals, with a significant rise in emergency medical admissions resulting from the respiratory illness that is affecting the whole of Scotland.

"We are working with clinical staff and colleagues in primary care to ensure that all patients are seen, assessed, treated and admitted where appropriate.

"We have escalated our winter plans to cancel some elective admissions but are continuing with urgent and cancer inpatient procedures.

"All day case procedures are continuing as normal."

'Turned away'

Patients were urged to use "appropriate" health services through their pharmacist, GP and out-of-hours service, and are also being advised that attendance at the hospitals should be for emergencies.

The health board has faced criticism over a decision to shut one of its three casualty units, at Monklands, as part of a �300m plan to reorganise services in the area.

SNP health spokeswoman Shona Robison MSP said that Tuesday's closure showed "a desperate need" to retain three A&Es in Lanarkshire.

"It is inconceivable that closing Monklands A&E should remain an option," she said.