In UK, no-fly zone has been imposed over parts of Northern Ireland causing renewed disruption for air travellers. The move by the Civil Aviation Authority comes as a dense volcanic ash cloud from Iceland drifts over north-western parts of the UK. Travellers are being advised to check with their airline before leaving home. In the south of Ireland, Donegal, Sligo and Knock airports are expected to be closed. The Department of Transport has warned that there is a chance that airports in south-east England may be also be affected in the next few days. Transport Secretary Philip Hammond said the situation is fluid but passengers' safety is the top priority. Ash from the Eyjafjallajokull volcano has caused disruption to thousands of flights since April.