External Affairs Minister Sushma Swaraj on Monday expressed grief over the loss of life and damage caused by a tsunami that hit the coast Sunda Strait in Indonesia killing 281 people.

“My deepest condolences to the families of victims who lost their lives in the Tsunami… Our prayers are with them as we stand by our Indonesian brothers in this hour of grief,” she tweeted.

On Saturday, giant waves crashed into coastal towns on the islands of Sumatra and Java, killing at least 281 people and injuring 1,016.

Hundreds of buildings were destroyed by the wave, which hit the coast of southern Sumatra and the western tip of Java about 9:30 pm (1430 GMT) on Saturday after a volcano known as the “child” of Krakatoa erupted, national disaster agency spokesman Sutopo Purwo Nugroho said.

It is thought that volcanic activity set off undersea landslides which in turn generated the killer waves. Saturday’s tsunami struck without a warning.

Anak Krakatau erupted again on Sunday, spewing ash and smoke. Death toll steadily rose through the day as more and more bodies were recovered.

Prime Minister Narendra Modi on Sunday expressed his grief at the huge calamity. “Saddened by the loss of lives and destruction in Indonesia caused by the Tsunami after the eruption of a volcano.

“Condolences to the bereaved families and wishing the injured an early recovery. India is ready to assist our maritime neighbour and friend in relief work,” he tweeted Sunday evening.

Social media went viral with images of video shot from a charter plane that captured the magnitude of the volcanic event in the Sunda Strait, between Sumatra and Java.

Coastal residents near Indonesia’s Anak Krakatau volcano were again warned on Monday to keep away from beaches amid fears it could trigger a new tsunami.

Indonesia is one of the most disaster-prone nations on Earth due to its position straddling the so-called Pacific “Ring of Fire”, where tectonic plates collide.

Most recently in the city of Palu on Sulawesi island a quake and tsunami in September killed thousands of people.

On December 26, 2004 a tsunami triggered by a magnitude 9.3 undersea earthquake off the coast of Sumatra in western Indonesia killed 220,000 people in countries around the Indian Ocean, including 168,000 in Indonesia.

(With agency inputs)