The Icelandic ash cloud causing chaos for air travellers in northern Europe has blown from Britain towards Germany, forcing airports in the north of the country to close.

Weather officials said there would be no takeoffs or landings at the northern Bremen and Hamburg airports early on Wednesday due to increased levels of ash in the atmosphere.

Authorities said it may be necessary to halt all air traffic coming and going from Berlin's airports, as well as Hannover, depending on the winds.

Some 700 flights are expected to be cancelled in Germany, the head of network operations for Eurocontrol said, but the situation could return to normal by Thursday.

Around 500 flights were grounded on Tuesday as ash from the Grimsvotn volcano was carried across northern England, Scotland and Northern Ireland.

But the ash was expected to clear from British airspace on Wednesday, air traffic control experts said.

"Latest information from the Met Office shows that following the recent eruption of Grimsvotn in Iceland, no volcanic ash is currently predicted in airspace over the UK from 01:00 UK time [02:00 GMT] on Wednesday May 25," British air traffic control company, National Air Traffic Services (Nats), confirmed.

Barnaby Phillips, Al Jazeera's correspondent in Kirkjubaejarklaustur, a village close to the volcano, said

"Iceland's meteorological office are saying from all their radar, their various intruments... that ash emissions from the Grimsvotn volcano have stopped, and they're only seeing steam coming out.

"They [told] us that this is consistent with the kind of activity that you see at the end of volcanic activity. So it does seem good news."

The ash cloud caused minor air traffic disruption in Norway and closed a small part of Denmark's airspace on Tuesday. Eurocontrol, Europe's air traffic control hub, warned there was a "strong possibility" that it would spread to southwest Sweden by Wednesday.

'Low impact'

"This would have some impact on flights. However, given the new procedures in place and the predicted movement of the ash cloud over the coming days, the actual impact on flights is expected to be relatively low," it said.

The disruption comes barely a year after a similar eruption in Iceland forced the biggest closure of European airspace in modern aviation history.

Authorities say the ash can damage planes and stop engines, but Ryanair, an Irish budget carrier, flew a plane through Scottish airspace on Tuesday and said it had detected no ash on the aircraft.

It accused British and Irish authorities of over-reacting but reluctantly cancelled its flights to and from Scotland - almost 70 in total.

British Airways conducted its own "verification" flight later on Tuesday, sending out an Airbus A320 from Manchester Airport to assess the risk over northern England and southern Scotland.

European Union transport commissioner Siim Kallas played down fears that the situation could get as bad as in 2010, when thousands of travellers from around the world were left stranded.

"We do not at this stage anticipate widespread airspace closure and prolonged disruption like we saw last year," Kallas told a news conference.

Iceland's Meteorological Office said activity at the volcano had slowed on Tuesday, and an Icelandic crisis management official said the plume of ash had fallen from its peak altitude of 20 km  to two km on Tuesday evening.

Source: Al Jazeera and agencies