(CNN) -- Iceland's Meteorological Office on Sunday lowered the aviation threat level from the Bardarbunga volcano from the highest level, red, down to orange.
With the lowering of the aviation threat level, all restrictions on air travel in Iceland have now been canceled and all airports in the country are open, according to the government.
On Saturday, the agency raised the alert level for Bardarbunga to red, which means an eruption is imminent or in progress. But the country's Civil Protection Department said on its website Sunday that a subglacial eruption, thought to be under way Saturday, did not occur.
The department said the seismic activity recorded under the ice cap of a glacier there could be something else, although an eruption is still possible. Seismic activity continues at the volcano, with two large earthquakes hitting overnight. Both measured over a 5 magnitude, the Civil Protection Department said.
Scientists have noticed an increase in seismic activity over the past seven years around the volcano, located in the northwestern region of the Vatnajokull glacier, one of Europe's largest glaciers, the Meteorological Office said.
The level dropped a little after the eruption of another volcano at the same glacier, Grimsvotn, in 2011, but has since picked up again.
According to the Smithsonian Institute Global Volcanism Program, Bardarbunga last erupted in 1910.
If it should blow its top again, it could be bad news for travelers.
Volcanic ash can be a serious hazard to aircraft, reducing visibility, damaging flight controls and ultimately causing jet engines to fail.