Indonesia'a Mount Gamalama volcano on Sunday, spewing ash one kilometre up into the sky, reports said. The 1,715-metre volcano on Ternate island erupted at 0215 local time (0515 GMT), limiting visibility and covering the city of Ternate with ash. Nearby residents were not asked to evacuate and no casualties were reported. Volcanic activity had been on the rise since yesterday, MetroTV reported. The Indonesian archipelago is situated along the seismically active Ring of Fire in the western Pacific Ocean and has the world's highest density of volcanoes. Of its 500 volcanoes, 128 are active and 65 are listed as dangerous .