New Delhi  - India's Congress Party was leading in key state elections Thursday in the first major electoral test after the general elections in April-May.

The Congress Party, leading partner in the federal ruling alliance, looked set to sweep the elections in the north-eastern state of Arunachal Pradesh while it was leading in the northern state of Haryana, according to India's Election Commission.

In the politically important western state of Maharashtra, the Congress Party along with ally the Nationalist Congress Party looked set to win, with the opposition Hindu right-wing Bharatiya Janata Party (BJP) and its ally Shiv Sena trailing.

A breakaway faction of the Shiv Sena, the Maharashtra Nirman Sena, looks set to win several seats along with independents, mostly rebel candidates who were refused tickets by the main parties.

The state elections saw a heavy turnout of 72 per cent of voters in Arunachal Pradesh days after neighbouring China objected to Prime Minister Manmohan Singh's visit to the state for campaigning, saying it was a disputed region.

China claims most of Arunachal as its territory while India says it is an integral part of the country.

The Congress Party-led United Progressive Alliance won a strong mandate in the general elections for the national parliament.

It is the incumbent party in Haryana and Arunachal Pradesh and rules Maharashtra in alliance with the Nationalist Congress Party.

A division of votes among the opposition parties strengthened the hands of the Congress Party in the state elections, analysts said.

A win for the Congress Party in even two of the three states is expected to strengthen Singh's hand in initiating economic reforms and rural development programmes. (dpa)