NEW DELHI (AFP) - - India's marathon elections entered the home straight Thursday, with millions voting in a fourth round of polling that saw the two main parties going head to head in a number of key swing states.

The penultimate phase of the five-stage election also brought in the Muslim-majority Kashmir Valley -- the cradle of the Kashmiri separatist movement where polls have long been snubbed as symbols of Indian rule.

A separatist boycott call, coupled with suffocating security, meant a very low turnout in the Kashmiri summer capital Srinagar, where voters were vastly outnumbered by the thousands of soldiers and police on duty.

Thursday's voting encompassed the capital New Delhi and the neighbouring states of Rajasthan and Haryana, as well as Communist-run West Bengal where sporadic clashes and attacks on polling stations left three people dead.

In the 2004 general elections, the ruling Congress party dominated in Delhi and Haryana, while its main rival, the Hindu nationalist Bharatiya Janata Party (BJP), took most the seats in Rajasthan.

A significant swing in any of these races could have a major impact, with many observers predicting that just a handful of seats could separate the two parties once all the votes are counted.

India's 714 million registered voters will decide a total of 543 parliamentary seats, in what is touted as the largest democratic exercise in the world.

The election -- staggered for reasons of logistics and security -- began on April 16 and ends on May 13. Final results are expected three days later.

With the finish line now in sight and no clear winner expected, attention has already turned to the political horse-trading to come when parties scramble for coalition partners to govern India's 1.1 billion people.

Neither the Congress-led alliance nor the bloc headed by the BJP is seen as capable of securing an absolute majority.

The inevitable post-poll rush for more allies is expected to witness the emergence of a shaky, vulnerable coalition at a time when many in India are looking for strong, policy-driven government.

"These are uncertain times," the Times of India said in an editorial. "And when the numbers games have been played out, let's remember there are policies to be made and implemented with determination."

The new administration faces a sharp economic downturn after successive years of growth, as well as numerous diplomatic challenges that include the deteriorating situation in neighbouring Pakistan.

In Srinagar, troops used teargas and batons to disperse rock-throwing protesters defying a massive security clampdown, police said.

A number of prominent separatist leaders who helped organise a wave of protests in recent days were also under house arrest.

Kashmiri Chief Minister Omar Abdullah said his only responsibility was to ensure people had the opportunity to cast their ballots.

"As long as I can provide an environment where there is little or no violence, and where people are free to come out and choose to vote or not to vote, that is as much as can be expected from me," Abdullah told AFP.

"It's not my job to force people to come out and vote."

Final turnout in Srinagar was put at 24 percent, which was slightly higher than 2004, but still low enough for the separatist movement to claim success for its boycott call.

"There is no use in voting," Ghulam Mohammed, a 55-year-old shopkeeper, told AFP. "Politicians have never kept their promises. No one hears our voice. We want 'azadi' (freedom)."