The volcano that sparked the ash crisis causing chaos across Europe's skies is quiet but it is "too early to say this is over", an Icelandic expert has said.

The eruption of Eyjafjallajokull on April 14, which sent the cloud of ash into the sky, was the first in nearly 200 years and led to an estimated 10 million travellers being grounded around the world.

Icelandic Civil Protection Agency official Iris Marelsdottir said some steam was coming out of the volcano, but no ash.

"Now we can only wait and see," she said. "It's too early to say this is over, but at the moment it is quiet."

A report by the Icelandic Met Office said there were no reports of ashfall at the site on Sunday.

It stated: "Volcanic tremor is still decreasing and is approaching the level it had before the eruption."

The ash crisis led to air traffic control company Nats handling 21.2% fewer flights last month compared with April 2009.

At one stage in mid-April the ash levels were severe enough to prohibit all flights to and from UK airports.