By Sanjoy Majumder BBC News Online correspondent in Srinagar

The assassination of Law Minister Mushtaq Lone in Indian-administered Kashmir is a major setback for the poll process.

Mr Lone was killed while addressing a campaign rally in his constituency in the northern district of Kupwara.

The killing will install fear in potential voters

Initial suspicion has fallen on Pakistan-backed militants who want to disrupt the elections.

The minister's death comes just days before the first phase of voting in crucial elections to the state legislative assembly in Indian-administered Kashmir.

The vote is being seen as a test for India's stand over Kashmir.

Delhi argues that holding elections is an important step towards peace in the disputed region.

Violent area

Kupwara district, where the killing took place, is north of Srinagar and close to the Line of Control which separates Indian and Pakistani Kashmir.

It is one of the most sensitive parts of the state with a history of violence.

Earlier this month, an independent candidate was killed in Handwara, which is in the same district.

Islamic militants are said to be very active in the area which is mountainous, making it difficult for the security forces to patrol the region.

Setback

Observers say the elections were greeted with enthusiasm in the area, marking a departure from earlier polls which had evoked little response from local residents.

Campaigning could be scaled down

Mushtaq Lone, who belongs to the ruling National Conference, was facing a stiff challenge from a former separatist in a contest that was being keenly watched.

But the latest attack comes as a major blow, with few people now likely to come out to vote.

The militants have threatened to attack potential voters and few are likely to take the risk.

It is also likely to increase pressure on the already over-stretched security forces.

India has poured in thousands of troops to ensure that the vote is peaceful, something that looks increasingly less likely.

Campaign blow

Mr Lone's assassination is the most high profile attack in what is already turning out to be a violent run-up to the elections.

Several party activists have been killed in the past couple of weeks and observers say election rallies are likely to attract fewer people now.

Many candidates are expected to scale down their campaign programme in the face of these attacks.

Analysts say a low voter turn-out will help the ruling National Conference retain its mandate - it is the only party with the resources and support on the ground to ensure its committed voters cast their ballots.

But the violence and a possible poor voter turnout will also concern the Indian Government.

It desperately wants these elections to be a success to retain its credibility internationally.

Delhi has publicly stated that these polls will be free and fair, even acknowledging that previous elections were less than perfect.

But Wednesday's violent attack is already threatening to cast its shadow on the vote.