LONDON - Two German airports halted flights on Wednesday as ash from an Icelandic volcano drifted across northern Europe, but traffic across much of the region started to return to normal.

The weekend eruption of the Grimsvotn volcano forced the cancellation of some 500 European flights on Tuesday, with Scotland especially hard hit.

The volcano seems to be losing steam, but the ash plume continues to affect some air travel.

In northern Germany, Hamburg and Bremen airports cancelled takeoffs and landings, and German authorities said Berlin terminals could also face closure.

"Currently there is no forecast when the restriction will be lifted," Hamburg airport said on its website.

Grimsvotn erupted on Saturday, and smoke belched as high as 20 kilometers into the sky. The eruption is its most powerful since 1873 and stronger than the volcano that caused trouble last year.

In Iceland, however, volcano experts said the eruption was easing.

President Olafur Grimsson told the BBC: "The volcano seems to be calming down. The eruption is gradually being diminished, and the ash cloud is definitely smaller than it has been."

While the ash has disrupted travel plans, including the state visit of US President Barack Obama to Britain, it has not created the kind of chaos caused by an Icelandic volcano last year when more than 10 million people were hit by a six-day European airspace shutdown. That cost airlines $1.7 billion.

But the eruption has exposed disarray among the authorities who decide on aviation safety as they try to apply new rules to avoid another mass closure of European airspace.

New procedures put the onus on airlines to make judgments on whether it is safe to fly through ash, in coordination with the forecasting authorities and civil aviation bodies.

Reuters