LONDON: Heavy snowfall blanketed parts of Britain on Monday, disrupting airports, train networks and roads in London while two coal plants have been put on standby in case of a power crunch over winter.

Operations in many parts of the city's underground network were either suspended or faced delays while motorways witnessed gridlocks due to snow. London's Gatwick and Stansted airports warned that the conditions could disrupt flight schedules.

The Met Office issued yellow weather warning for snow and ice in London and south-east England, with ice and fog warnings in other parts of England and the whole of Northern Ireland.

The snow caused issues for commuters and holidaymakers at the start of a fortnight where rail workers and border officials plan industrial action.

Southeastern, which operates rail services into London, advised passengers not to travel due to severe disruption caused by snow and ice.

Meanwhile, Britain's National Grid on Monday issued a notification to warm two winter contingency coal plants.

"This measure should give the public confidence in Monday's energy supply," the National Grid said, adding it was not confirmed the plants would be needed, but they would be ready.

Emergency services said they had responded to a "serious incident" near Birmingham as they reminded people to take care in the potentially hazardous conditions.

"Four children have been taken to hospital in a critical condition after being rescued from an ice-covered lake," West Midlands Ambulance Service said adding they had been called to the lake in Solihull, central England, on Sunday afternoon.