Bodies are still being found almost three full days after the tsunami struck without warning on Saturday evening, and the search area is still being expanded to more remote areas only now found to have been hit by the killer wave.
Indonesia, a vast archipelago of more than 17,000 islands with a population of some 260 million people, sits on the geologically active "Ring of Fire" and is frequently hit by earthquakes and tsunamis.
Bad weather conditions, endless rain and high waves have hampered his search efforts since Monday night.
The head of his agency, Dwikorita Karnawati, warned people to stay 500 metres to one kilometre from the coast.
Meanwhile, the number of those displaced by the volcano-triggered tsunami rose sharply to over 20,000 after a warning of possible further giant waves, officials of the disaster agency said here on Wednesday.
It was the second time in three months that a tsunami has clobbered Indonesia.
Separately in Aceh province of northern tip of Sumatra Island of western Indonesia on Wednesday, people marked the 14th anniversary of the 2004 Indian Ocean tsunami, which killed some 226,000 people, including 170,000 in Aceh province. Military and volunteer teams used drones to assess the extent of the damage along the coast.
Thousands of people have taken temporary refuge in shelters like mosques or schools. Rice and instant noodles have been delivered to many shelters, but clean water, wet weather gear, fresh clothes, and blankets are in short supply, some evacuees said. Unlike many other news organizations, we have not put up a paywall.
Other residents of the same emergency camp, like Tarini, a mother of four, told Reuters their families had been left with nothing but the clothes on their backs. "I could no longer hold my girl", she said. "All we can do from here is to pray for them".
He stated that many charity groups from across the world also wanted to come to the disaster-affected areas "but the government as a regulator has not given permission unless they become partners of local NGOs".
The death toll in Indonesia has climbed above 400 in the wake of a devastating tsunami that struck the Southeast Asian nation on Saturday.
The waves engulfed fishing villages and holiday resorts, leaving a coast littered with the matchwood of homes, crushed vehicles and fallen trees.
NPR reported that Indonesia's National Disaster Management Agency said the country's tsunami warning system has been broken since 2012 due to lack of funding, damage from passing ships and vandalism.
The meteorology agency said that an area of about 64 hectares, or 90 soccer pitches, of the volcanic island had collapsed into the sea.
Sunday's event, coupled with an quake and tsunami in September on Indonesia's Sulawesi island that killed at least 2,100 people, triggered flashbacks for some who survived the 2004 tragedy.
The Anak Krakatau is an island that emerged in 1927 and has kept growing since then.