BANGKOK, Thailand (AP) – Flash floods triggered by days of heavy rain killed at least 50 people in mountainous northern Thailand and left thousands trapped on rooftops and in trees, officials said Tuesday.

Other victims were believed trapped under tons of mud from a landslide that engulfed dozens of houses in the Lablae district of Uttaradit province.

Tens of thousands of households had no power.

“The situation is still confused because in several areas the rescue teams have not yet arrived and electricity is cut off in the entire Lablae district,” said Saman Pangwatcharakorn, chief of the province’s disaster prevention and rescue center.

By Tuesday evening, some 40 bodies had been recovered in Uttaradit and another 40 people were listed as missing, Saman said.

Boonrieng Uthairat, chief of the province’s health office, said in a radio interview that the number of people killed in his province – the worst-hit by three days of rain – may hit 100.

“We believe that the death toll will rise because rescue teams are still unable to get into villages where the landslide hit the houses of villagers,” said Nitipat Pimpiriyakul, chief of the province’s disaster center.

Ten more people were killed in two other provinces as the floods inundated several towns and caused landslides, Boonrieng said.

More than 2,000 other people in the district were trapped on the roofs of their houses or in trees, Nitipat said.

Thousands of people in Lablae are without food and electricity and rescue teams in boats have not reached them. As many as 50,000 households in Uttaradit, Sukhothai and Phrae provinces are without power.

More than 1,000 passengers were trapped inside four trains stranded in Uttaradit stations with food running out, said Montakan Sriwipas, a spokeswoman for the state railways.

Railway service to northern Thailand has been suspended, Montakan said.

Uttaradit is about 280 miles north of Bangkok.

Prime Minister Thaksin Shinawatra, who resumed his official duties Tuesday after a seven-week leave of absence, was scheduled to inspect the disaster scene Wednesday.