New Delhi: A high security red alert was announced here Thursday after two bomb blasts on a train in Chennai killed a young woman and injured 14 people. "Security has been tightened at all railway stations, bus stations, crowded markets and other important places," Delhi Police spokesperson Rajan Bhagat told IANS. A young woman was killed and 14 people were injured Thursday when the bombs went off in quick succession in two coaches of the Bangalore-Guwahati train at the Chennai station.