The volcanic ash plumes which grounded millions of air passengers around the world last month could be making a comeback.<br /><br />Most airports in Spain and Portugal have grounded flights again because of possible safety concerns.<br /><br />Al Jazeera's Nazanine Moshiri reports on the Eyjafjallajokull ash cloud as it continues to billow smoke and wreak havoc.<br /><br />[May, 08, 2010]
