Airspace across Europe remains closed today despite air traffic control body Eurocontrol claiming the volcanic ash cloud has started to thin.
There had been hopes air travel may return to normal as the cloud dispersed over the Mediterranean and Scandinavia.
Italy reopened its airspace at 7am local time this morning but was forced to close it again just two hours later.
Germany, Italy, Spain and Eastern Europe had seen some services over the weekend with the backlog of flights likely to take a long time to clear.
Some pilots have been critical of the safety measures being taken arguing modern aircraft are designed to cope with bird strikes, hail, dust storms and even salt spray.
Several airports sent up test flights over the weekend to assess the possible danger of resuming commercial services.