NEW DELHI (AP) — Rescuers in rafts and boats were searching a Himalayan river Monday for dozens of Indian students swept away when a dam released a rush of water without warning, and police said four bodies had been found.

The 25 students from the southern city of Hyderabad had been taking photographs Sunday evening on the banks of the Beas River when they were hit by the rush of water from the Larji hydropower station near the mountain resort town of Manali in Himachal Pradesh.

They had been part of a larger field trip of some 48 students spending 10 days near Manali. Some students at the river managed to scramble to safety.

"We saw a wall of water hit those who were on the banks. They fell flat and disappeared under the waves," a student identified only as Sumiran told The Indian Express newspaper.

Kiran Kumar, a professor who was accompanying the students, said he saw the water level rising and told the students to step back from the bank. But "within one or two seconds, the water level increased all of a sudden. Some of the students were washed away right in front of me," he told the AP.

Police in Manali said four bodies were recovered Monday morning after the search resumed at dawn. They said a shortage of boats and divers was hampering the operation.

"Officials there are fearing the chances of finding survivors were slim," said Anurag Sharma, police director general in Telangana state, where Hyderabad is located.

Himachal Pradesh Chief Minister Virbhadra Singh demanded the dam's engineer be suspended while the incident is investigated.

Telangana's government on Monday sent police officials and parents of the missing to the search site, 530 kilometers (330 miles) north of New Delhi.

Anxious friends and relatives gathered at Hyderabad's Vigyan Jyothi Institute of Engineering and Technology waiting for news of the missing.