Prime Minister Manmohan Singh has declared victory in India's national elections. He says voters have given the Congress party-led coalition a "massive mandate."

Celebrations have already begun outside the Congress party office.

Its United Progressive Alliance achieved a sweeping success in the month-long polls.

This will keep Prime Minister Manmohan Singh in power for another term.

Singh was joined on Saturday by Congress party chief Sonia Gandhi in thanking the Indian people for their trust.

Manmohan Singh said, "In this moment our first thoughts go the generosity of the people of our country, we express our gratitude to them for having reposed their faith in our party. It will be our effort to rise to the expectations of our people."

Computerized vote counting began at eight in the morning at over 1000 centers across the country.

Observers and micro-observers are conducting a random check at the end of every round of counting.

The main opposition BJP has conceded defeat.

Balbir Punj, BJP spokesperson, said, "Based on the trends, we accept that Congress and UPA have gained over us."

The month-long elections saw a total voter turnout of about 60 percent.

A new parliament will be in place by June 2.