At least eight civilians were killed on Sunday when security forces in Indian-administered Kashmir opened fire on protesters during a by-election, according to officials.

Local rebel leaders had called for a boycott of the vote, which was held to fill a vacant seat after a member of parliament resigned to protest against the killing of civilians during a sweeping security crackdown last year.

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State and paramilitary police fired bullets and shotgun pellets as thousands of protesters shouting slogans against Indian rule charged into voting booths in Budgam district near the main city of Srinagar. Protests spread to Srinagar when reports of the first killings came from the Charare-e-Sharif area of Budgam.

Waheed Para, spokesman for the ruling People's Democratic Party (PDP), told Al Jazeera eight people were killed in the clashes.

Dozens of other civilians and government personnel were also wounded, according to Shantmanu, the state's chief electoral officer.

Officials said protesters threw petrol bombs and stones, and set voting machines and government vehicles ablaze.

More than a dozen polling stations were shut owing to violence.

"This is a reaction to what is happening in Kashmir, because people are getting killed mercilessly," a young protester in Srinagar, who declined to give his name for fear of reprisal, told Al Jazeera.

"The youth are coming out to express our anger and dissent in every way possible," he added.

Para, the PDP spokesman, said: "We regret these killings. It will take some time to bring back a conducive environment in the state."

Record low turnout

Kashmir has been divided between India and Pakistan since the end of British rule in 1947. Both claim the disputed territory in its entirety. Most people in India's portion favour independence or a merger with Pakistan.

Only 6.5 percent of voters on Sunday turned out to cast their ballot, Shantmanu said, 26 percent less than in the last elections held in 2014 and the lowest ever participation recorded in any election in the disputed territory.

A 40-year-old shopkeeper in Srinagar, who spoke to Al Jazeera on the condition of anonymity, said he did not cast his vote because "these elections don't mean anything".

"If any change is to happen in Kashmir, politicians should bring a political revolution of the Kashmir dispute."

Ahead of polling, authorities suspended internet services across the Kashmir valley for three days for fear of protests. The Indian government also sent in 20,000 additional paramilitaries to augment the 500,000 soldiers deployed there.

Police had also detained hundreds of young people and separatist activists in the run-up to the poll, sources told AFP.

The by-election in Srinagar was held to fill a seat in the Lok Sabha, India's lower house of parliament. A second by-election in the state for a separate Lok Sabha seat is set to take place on April 12 in Anantnag.

The results of both polls are expected to be announced on April 15.

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Rebel groups in Indian Kashmir have for decades battled with troops and police, demanding independence or a merger of the territory with Pakistan.

India accuses Pakistan of backing separatist fighters - a charge Islamabad denies.

Armed encounters between rebels and government forces have become more frequent since the killing of a popular rebel leader by security forces last July sparked widespread unrest.

The violence has killed scores of civilians and wounded more than 12,000 civilians and security force personnel.

Fahad Shah contributed to this report from Srinagar.