BERLIN (AFP) – Airlines have lost around 1.7 billion dollars after a “week without revenue” because of the chaos caused by volcanic ash, the head of the International Air Transport Association (IATA) said Wednesday.

At the height of the upheaval on Saturday and Sunday, carriers were losing 400 million dollars per day, Giovanni Bisignani told reporters in Berlin, calling an earlier estimate of 200 million dollars per day “conservative.”

The sector has also been left to pick up additional costs like providing accommodation to stranded customers, food and alternative modes of transport to get them home, Bisignani said.

“We’ve seen a week without revenue but that has not stopped the costs,” he said.

He said that in Europe “governments must take their responsibility” and help the carriers, calling the firms victims of “an act of God, completely out of the power of the airlines.”

He said however that the situation was different from the aftermath of the attacks on the United States on September 11, 2001, when airlines were bailed out by governments.

After 9/11, “it took a long time to recover because it was an issue of confidence,” Bisignani said, saying he hoped that the chaos of the past week was a “parenthesis.”

European air travel was slowly returning to normal on Wednesday after volcanic ash drifting from an eruption in Iceland prompted a shutdown last week that left millions of passengers stranded and hit the economy.

The chief executive of Lufthansa, Europe’s biggest airline by passenger numbers, said that the firm had no estimate on how much the stoppage had cost the firm but that it was “not marginal.”

“We don’t need a bailout, we don’t need an umbrella” but as an industry “we’ll have to make up our mind” on whether we want state aid or not, Wolfgang Mayrhuber told the same event in the German capital.

Asked how fast he thought the sector would recover, Mayrhuber said: “(The) volcano will not change the desire and need to travel.”