Hasina's ruling Awami League party and its allies won 288 seats in the 300-seat parliament, with the main opposition securing only six seats, Election Commission secretary Helal Uddin Ahmed said.

Sunday's vote, which hands Hasina a record fourth term, was overshadowed by clashes between rival supporters that killed at least 17 people and allegations of ballot box stuffing and intimidation at polling stations.

Hasina's government had mounted a crackdown on the opposition, an alliance led by the Bangladesh National Party (BNP), which urged the country's election commission to void the results.

"We are demanding that a fresh election is held under a neutral government as early as possible," Kamal Hossain, who heads the alliance, told reporters.

Deadly violence that blighted the election campaign spilled over into voting day, even as authorities imposed tight security with 600,000 troops, police and other security forces deployed across the country.

Thirteen people were killed in clashes between Awami League and BNP supporters, police said, while three men were shot by police who said they were protecting polling booths.

An auxiliary police member was also killed by armed opposition activists, according to officials.