REYKJAVIK, Iceland (AP) — Icelandic authorities briefly raised the aviation warning code to red Friday after a small fissure eruption near Bardarbunga volcano, but no volcanic ash was detected by the radar system.

The eruption took place the Holuhraun lava field, five kilometers (three miles) north of Dyngjujoekull glacier, Iceland’s Meteorological Office said. The event was described as being not highly explosive — and thus not producing much of the fine ash that can affect aircraft engines.