Jakarta – Indonesia's disaster agency warned on Thursday of more deaths after torrential rains pounded the Jakarta region, triggering floods and landslides that killed at least 23 and left vast swaths of the megalopolis underwater.Tens of thousands of residents have been evacuated to temporary shelters in the area, home to some 30 million, with scores of homes damaged.Images from across the region showed waterlogged homes and cars covered in muddy floodwaters, while some people took to paddling in small rubber lifeboats or tyre inner-tubes to get around.At least 21 people died in greater Jakarta, while two more were killed by flash floods in neighbouring Lebak regency, at the south end of Java island."The latest toll is 21 dead," social affairs minister Juliari Peter Batubara told reporters on Thursday."We hope the toll won't keep going up," he added.'Hit without warning'In Lebak, the local disaster agency said it had confirmed two residents died and it was investigating reports that three more people perished.Police in Lebak said that they were searching for as many as eight people who could still be missing from the area.Around Jakarta, an eight-year-old boy killed in a landslide and an 82-year-old pensioner were among the confirmed victims.Those killed died from drowning, hypothermia and being covered by landslides, while one 16-year-old boy was electrocuted by a power line."The floods hit without warning," Munarsih, who goes by one name, said from her waterlogged neighbourhood in Jakarta's western outskirts, where dozens of local families fled to safety."The water came very fast and it rose quickly. We couldn't manage to get our stuff out, including my car," she added.31 000 people evacuatedOn Wednesday, electricity was switched off in many Jakarta districts to prevent more electrocutions, with some train lines and one of the city's airports also shut.The torrential downpour triggered landslides on the city's outskirts.The disaster marked Jakarta's worst flooding since 2013 when dozens were killed after the city was inundated by monsoon rains.The city is regularly hit by floods during Indonesia's rainy season, which started in late November.Authorities said on Thursday that some 31 000 people had been evacuated, but that figure did not include residents in Jakarta's satellite cities.Service at Halim Perdanakusuma airport, which handles commercial and military planes, was temporarily shut due to severe flooding on its runways, according to the transport ministry. It was reopened on Thursday.Some flights were transferred to Jakarta's main Soekarno-Hatta International Airport.