Precarious search and rescue effort under way on outskirts of Hiroshima city after rain-soaked hillsides give way

At least six people were confirmed dead and 22 were missing after rain-soaked hills in the outskirts of Hiroshima gave way early on Wednesday in several landslides.

Video footage from the Japanese national broadcaster NHK showed suburban homes in the western Japanese city surrounded by streams of mud and debris, and residents picking their way over piles of rocks and dirt.

Rescue workers suspended by ropes from police helicopters were pulling victims from the rubble as they searched homes stranded amid piles of timber from crushed houses. The fire and disaster authority, citing the local government, said six people were confirmed dead and another 22 were missing as of late morning. It said at least 20 people were injured, one seriously.

Japanese media, citing local police, put the death toll at 32.

“A few people were washed away and it is hard to know exactly how many are unaccounted for,” said local government official Nakatoshi Okamoto, noting that the conditions in the disaster area were hindering efforts to account for all those affected.

Facebook Twitter Pinterest Aerial view of the damage from a landslide in the Asaminami ward of Hiroshima. Photograph: KYODO/REUTERS

Authorities issued warnings that further rains could trigger more landslides and flooding.

Landslides are a constant risk in mountainous, crowded Japan, where many homes are built on or near steep slopes. Torrential rains in the early morning apparently caused slopes to collapse in an area where many of the buildings were newly constructed.

Damage from land and mudslides has increased over the past few decades due to more frequent heavy rains, despite extensive work on stabilising slopes. In the past decade there have been nearly 1,200 landslides a year, according to the land ministry, up from an average of about 770 a year in the previous decade.

In October 2013 multiple mudslides on Izu-Oshima, an island south of Tokyo, killed 35 people, four of whose bodies were never recovered. Those slides followed a typhoon that dumped a record 824mm (more than 32 inches) of rain in a single day.