Britain and France further extended no-fly restrictions Saturday as an ash cloud spewing from an erupting icelandic volcano continued to affect air travel across Europe, the two country's aviation officials said. Flights in and out of Britain will remain grounded until at least 01:00 a.m. (0000GMT) Sunday, the country's National Air Traffic Service (NATS) said in a statement, noting 'current forecasts show that the situation is worsening throughout Saturday.' However, domestic flights may be able to take off from Scotland and Northern Ireland, whose flight restrictions had been lifted on Friday evening, but were reapplied overnight, NATS said. In France, three airports in Paris and 23 others in the rest of the country will keep closed until 8:00 p.m.(1800 GMT) Saturday, according to French civil aviation officials. Meanwhile, the huge volcanic ash cloud also forced Ukraine, Belarus, and Poland to close their airspace on Saturday. As the cloud was moving south and east, hundreds of thousands of passengers were stranded throughout Europe due to flight cancellations since Wednesday. There could be more travel restrictions, as an Icelandic geologist said activity has increased at the volcano, sending the ash plume to rise some 8.5 kilometers into the air. 