At least 22 people have been killed in election-related violence on the first day of voting for local assemblies in two northern Indian states.

The casualties - including at least 14 members of the security forces - came despite a heavy security presence in Bihar and Manipur.

Attacks in Bihar on Saturday claimed the lives of at least two troopers and two election officials.

On Friday night, suspected leftist guerrillas detonated a land mine in the south of the state, killing at least eight members of an armed militia deployed to counter election violence.

Bihar has a history of poll violence. During last year's general elections, more than 40 people were reported to have died on one day alone.

In Manipur, officials said at least five people, including two security personnel, were killed in two separate incidents.

The small north-eastern state will hold a second round of voting on 22 February.

Caste issues

Election officials said at least 60% of voters cast ballots in the state assembly elections, despite calls for a boycott by the secessionist National Socialist Council of Nagaland (NSCN).

At stake in Bihar were more than 100 state assembly seats, mainly in the south of the state.

Politics in the state is dominated by caste issues, in which traditional landed elites are pitted against lower caste groups.

Voting in Bihar is staggered over three weekends in order to allow the security forces to concentrate their efforts on specific areas.

The state has the second largest number of voters in India.

Among those standing are the flamboyant former Chief Minister, Laloo Prasad Yadav for the ruling Rashtriya Janata Dal (RJD) and a senior leader of the right-wing Bharatiya Janata Party, Sushil Kumar Modi.

The vote is regarded as the first significant popularity test for Prime Minister Atal Behari Vajpayee's BJP-led coalition since it took office last October following its victory in the general elections.

The BJP and its allies are attempting to unseat the RJD which has held power in the state for some 10 years.

Orissa and Haryana states are also holding elections to their assemblies in February.

Political analysts say the fortunes of the opposition Congress Party leader Sonia Gandhi will also be under scrutiny following the party's poor showing in the general elections last year.