London, Dec 22 (IANS) Airports across Europe are struggling to help thousands of stranded passengers after severe weather paralysed the continent’s transport network in the past few days.

Freezing temperatures, snow and ice have grounded flights and disrupted plans of holiday makers going home for Christmas.

Airport operators across the continent have, however, defended their handling of the crisis amid criticism from the European Commission.

Officials at the worst-affected airport – London’s Heathrow – rejected offers to bring in the British Army to help, BBC reported Wednesday.

Since Saturday, when 12.7 cm of snow fell in just an hour, Heathrow has cancelled hundreds of flights.

Airport operator BAA said both runways were now open but warned: ‘Airlines are currently operating a significantly reduced schedule while they move diverted aircraft and crew back into position.’

British Airways said that in line with a BAA directive, it would operate only a third of its flights at Heathrow until 0600 GMT Thursday.

In Ireland, the Dublin Airport Authority said the airport would be closed until at least 0800 GMT Wednesday, The Irish Times reported.

In Germany, Frankfurt airport cancelled 550 of almost 1,300 flights Tuesday because of bad weather.

Air France said some 5,000 people spent the night at Paris’ Charles de Gaulle airport Tuesday – 4,000 of whom were trying to fly to London, according to Le Monde.

In Sweden, Scandinavian airline SAS said flights to Heathrow were the most problematic.

‘It is the absolute worst there,’ SAS spokeswoman Elisabeth Manzi told The Local.

Many passengers sought to travel by rail instead of planes, causing Eurostar to recommend that passengers trying to leave from London should cancel their tickets and stay at home.

The European Commission said it was ‘extremely concerned’ about the level of disruption caused by the severe snow, saying that it was ‘unacceptable and should not happen again’.

But the Airports Council International (ACI) – the professional association of European airport operators – said 88 percent of flights to and from European airports had been operating.

It said airports in northern Europe found it easier to cope with severe weather because the temperatures there remained largely below freezing, so the condition of the runways did not change, whereas the fluctuating temperatures in western Europe had caused problems.

British Prime Minister David Cameron said he was ‘frustrated’ it was taking so long to get Heathrow fully operational again.

‘If it’s understandable that Heathrow had to close briefly, I’m frustrated on behalf of all those affected that it’s taking so long for the situation to improve,’ Cameron said.