Iceland's volcano is showing clear signs of having stopped erupting and no more ash is spewing from it, the country's meteorological office said on Wednesday.
The Grimsvotn volcano began erupting on Saturday and drifting ash has disrupted hundreds of flights in parts of Europe and the United Kingdom.
Germany has grounded hundreds of flights across its northern airspace. Bremen and Hamburg airports closed on Wednesday, with traffic at Berlin's airports due to stop later.
However, air traffic is returning to normal in other parts of northern Europe, a day after about 500 flights were cancelled.
An Icelandic official says volcanic activity seems to have stopped, but geophysicists have yet to make the call to declare the eruption finally over.
The eruption is Grimsvotn's most powerful since 1873 and stronger than the Eyjafjallajokull volcano that grounded tens of thousands of flights in April last year.