Mest lesið á RÚV
Scientists still say there is not definitive sign of a volcanic eruption having started. The rifts were spotted in the same area where seismic activity has been monitored by geologists since mid-August.
This story, by the Icelandic National Broadcasting Service (RUV), was updated on August 27. 2014, at 22.19 GMT.
Updates in English will be posted at: ruv.is/volcano. Follow us on Twitter @ruvfrettir