Police in the Indian capital, Delhi, closed the roads leading to the Congress head office because they were unable to manage the crowds gathering to celebrate the party's victory.
Supporters of the Congress, which is sweeping back to power in India, are in a jubilant mood.
Celebrations are going on with party supporters dancing, beating drums, bursting crackers and shouting slogans.
Congress supporters dance with delight in Delhi
One Congress supporter, Sanjay Sharma, said celebrations would go on late into the night, and last several days.
"It's a great comeback for our party. Our victory shows that people were not happy with the policies of the BJP government," Mr Sharma said.
Congress leader Jagdish Tytler, who won a seat from Delhi, distributed sweets to his supporters outside the Congress office before leaving for his victory march.
"It's a very special moment indeed for me. I owe my gratitude to the people of my constituency for believing me," Mr Tytler told the BBC.
Congress supporters in buses have been doing the rounds of the city celebrating their success.
Barely five kilometres away the office of the right-wing Hindu Bharatiya Janata Party (BJP), looked deserted.
The rooms of the office bearers were closed and security personnel could be seen sitting and fanning themselves with their hankies.
Sushil, who was in charge of the souvenir store inside the BJP headquarters, said the result was not expected.
"Most leaders have left the office now," he said.
People on the streets were using whatever means they could to get news updates of the election results.
Surinder Kumar, an auto rickshaw driver, said the BJP had paid the price for not helping the poor.
"The Congress party will definitely work for people like us though I did not expect their victory," he said, after hearing the news on the radio.
However, there are Congress supporters who are rejoicing over the win but have reservations about Italian-born Sonia Gandhi becoming the prime minister.
"This victory should be savoured. But the Congress party should be careful in choosing the person for the top post. Though Vajpayee was good, his party did not do anything for the common man," said Mohit Sharma, a grocery shop owner.
But Iknam Singh, working in a petrol station, lamented the loss of the BJP.
"It's a sad day. The BJP was doing a good job under the able leadership of Atal Behari Vajpayee," he said.
But, as the election results show, not many people in this country agree with his view.