Eleven students drowned and 10 others were rescued during a school outing for a river clean-up in Indonesia’s West Java province.

Local officials said on Saturday that 150 students, aged 13 to 15, were participating in the clean-up along the banks of the Cileueur river when 21 of them slipped into the water.

“The weather was good and there was no flash flood,” said Deden Ridwansyah, chief of the Bandung Search and Rescue Office. “Those children who drowned were holding each others’ hands. One of them slipped and the others followed.”

Residents and a rescue team managed to save 10 of the students, who were sent to a nearby hospital.

All victims were found and the search ended on Friday night.

The students apparently were not wearing flotation devices.

Some reports said they were trying to cross the river, which is popular for rafting and inner tubing, when they fell in.

Rescuers used big orange inflatable rafts to search for victims.

Rains cause frequent landslides and flash floods in Indonesia, where millions of people live in mountainous areas or near flood plains.

River trekking is banned for children and teenagers during the rainy season, which starts in late November.

In February last year, 10 scouts died after they were swept away by a flash flood that also left nearly two dozen injured.

(Al Jazeera)

•Relatives of students, who drowned while participating in a trekking activity of a scout group along the Cileuleur River, leave the morgue of a regional hospital in Ciamis on Friday