Iceland on Sunday issued an aviation alert after a fresh lava eruption from a fissure near the Bardarbunga volcano, but the warning was later lowered.
Iceland's Met Office said there had been "a very calm lava eruption... hardly seen on seismometers".
Planes were banned from flying within 6,000 ft of the volcano peak until the red alert changed to orange.
Iceland's Eyjafjallajokull volcano erupted in 2010, producing ash that disrupted air travel across Europe.
Sunday's eruption in the Holuhraun lava field area was "calm but continuous", authorities said.
It happened in roughly the same place as an earlier eruption on Friday morning, and is the third to happen in the area in the last week.
The latest eruption was more intense than Friday's with around 10 times more lava said Armann Hoskuldssonk, a geologist from the University of Iceland.
But the Met Office later said: "No ash has been detected. The Aviation Colour Code for Bardarbunga has therefore been reset to orange."
BBC transport correspondent Richard Westcott says that even if a big cloud of volcanic ash were emitted, it would not cause the same level of disruption to flights that brought Europe to a halt in 2010.
He says new equipment that airliners and engine makers have been testing would allow planes to identify and fly around ash clouds.