Kathmandu  - At least eight people were injured Thursday when two bombs exploded outside a college in southern Nepal, police said.

The bombs went off as students gathered outside Thakur Ram College in the town of Birgunj, about 90 kilometres south of Kathmandu.

There were no immediate claims of responsibility for the blasts, police said.

"The bombs exploded just as students prepared to vote to chose their representatives in college elections," the Birgunj police office said. "Eight students received shrapnel wounds."

Birgunj lies in the restive southern Nepalese Terai plains, where bombings, murders and extortion have become common.

More than two dozen armed groups operate in the area, seeking greater autonomy and rights for the ethnic Madhesi community. Several attempts by the government to bring the armed rebel groups together for peace negotiations have failed.

The blast came as 250,000 students in 170 colleges affiliated with Nepal's two universities began voting in student union elections, which are often accompanied by clashes among rival supporters.

There were reports of sporadic violence in many parts of the Himalayan nation as rival students clashed amid accusations of vote rigging. Dozens of students were injured in the clashes, police said.

Student unions in Nepal are closely affiliated with political parties, which see colleges as a base to recruit supporters.

A student union affiliated with the former Maoist rebels is contesting the polls for the first time.

In the past, student elections were largely dominated by unions close to the Nepali Congress and the moderate Communist Party of Nepal-Unified Marxist Leninist. (dpa)