Efforts are being made in the building of long tunnels in the Himalayan region, with Chinese companies setting a record by digging 1,503.3 meters of tunnel in a month at the Sunkoshi Marin Diversion Project in Sindhuli, Nepal, the Science and Technology Daily reported on Tuesday.

The water diversion project has been jointly undertaken by China Railway Second Bureau Group and China Overseas Engineering Group Company (COVEC).

The 13.3-kilometer tunnel is expected to become the world's first ultra-long and ultra-deep water diversion tunnel that passes through the Himalayas and the Kathmandu spiral formation.

A tunnel boring machine (TBM), also known as a "mole," has been used to cut through the hills so as to excavate the tunnels. The TBMs used in the project have achieved a single-month advance of 1,503.3 meters, breaking the world record set by the project team in 2023, the report said.

Chen Song, the Chinese Ambassador to Nepal, expressed appreciation for the efforts made by the Chinese companies.

Mitra Baral, head of the Sunkoshi Marin Diversion Project, said that 12.3 kilometers of tunnel digging work has been completed, according to local Nepalese newspaper Republica, and the tunnel will break through in May, he added.

The diversion tunnel will redirect part of the flow of the Sunkoshi River to the Bagmati River to irrigate farmland to the south of the outer foothills of the Himalayas, the local Kathmandu Post reported.

The project was first mooted on October 14, 2022. After completion, it will solve difficulties in agricultural irrigation and alleviate the current shortage of electricity in the area, which is of great significance for promoting the social development of the eastern region of Nepal.