Air India has resumed flights to the US and Jet Airways to North America. But, the flights for European destinations of all the airlines continue to remain suspended due to spread of volcanic ashes over Europe.<br/> <br/>An Air India spokesperson said that the Airliner resumed its flights from Delhi to New York and New York to Delhi and also Mumbai-New York and New York-Mumbai flights last night with a diversion through the polar route. <br/> <br/>A polar route refers to an aircraft route across the uninhabited polar ice cap region. <br/> <br/>Jet Airways has started its Delhi-Toronto and Mumbai- New York flights last night with a technical stop over at Athens in Greece.<br/> <br/>European officials have expressed hope that up to half of the flights across Europe could operate today as the cloud of volcanic ash from Iceland is moving. The European Transport Commissioner and Spanish Minister for Europe was speaking after talks with the air traffic agency Euro control which had recommended the current flight ban. <br/> <br/>Several European airlines have carried out test flights at high altitudes and reported no problems of volcanic ash. <br/> <br/>But a scientific test flights over Britain concluded that the situation could still be very dangerous. A British scientist said that at lower altitudes they found six different layers of ash. He said no one knew what the safe limit for flying was in these conditions.<br/><br/>