Himanta Biswa Sarma is credited for the win (File)

The BJP and its allies have swept the northeast. The party has won 14 seats and its allies have won four, making the NDA's total to be 18 out of the 25 Lok Sabha constituencies.

When BJP chief Amit shah had taken over as the national president, he emphasised in his first meeting that the BJP's growth in eastern India had to be from the Northeast. His plans have materialised.

The BJP had made the citizenship (amendment) bill a major issue in the northeast. The opposition contested the polls, attacking the BJP over it. The BJP, in the end, had the last laugh.

In 2014, the BJP had won seven seats in Assam and one in Arunachal Pradesh. The Congress had won three in Assam, five in the rest of the northeast.

The party also got a massive victory in the Arunachal legislative assembly polls.

Three former Congress chief ministers - KL Chisi in Nagaland, Nabam Tuki in Arunachal Pradesh and Mukul Sangma in Meghalaya have lost in the Lok Sabha election.

In Assam, however, Gaurav Gogoi was able to retain his Kaliabor seat for second consecutive term.

The party has also won the Nagaon lok sabha seat, where former Congress minister Pradyut Bardoloi had won.

BJP's Rajdeep Roy has defeated Congress heavyweight Sushmita Dev in Silchar.

For the BJP, retaining seats in the northeast was a major challenge as the party faced backlash over the citizenship bill issue, but it was able to come up with a strategy to turn the tide in its favour.

"In Assam and Northeast, we have clearly said that if the BJP is voted to power, we will bring the bill again. People realised that this is a serious bill that restores our civilization and that's why people across the east and northeast have accepted this and this results is in the favour of the citizenship bills," Himanta Biswa Sarma, the BJP's stalwart in the northeast, told NDTV.

The Congress has accepted its failure.

"On the citizenship bill issue, we could not reach out properly and they have been able to polarise the vote," said Tarun Gogoi.