Patna, Sep 17 - In a major setback to Bihar Chief Minister Nitish Kumar, the opposition alliance of Rashtriya Janata Dal (RJD) and Lok Janshakti Party (LJP) Thursday bagged eight seats in by-elections for 18 assembly seats in the state.

The ruling Janata Dal-United (JD-U) won three seats (Triveniganj, Bagha and Dhoraiya) and its ally the Bharatiya Janata Party (BJP) got two seats of Begusarai and Chainpur.

Contesting independently of its former allies RJD and LJP, the Congress managed victories in Chenari and Simribakhtiarpur. The party had turned down an alliance offer by the RJD.

However, the party put up a brave face with Congress general secretary Janardan Dwivedi saying: 'By-poll results are not an indicator of the people's mood.' He told reporters in Delhi that local issues play a major role in such polls.

Former railways minister Lalu Prasad's RJD won on Bochaha, Kalyanpur, Phulwarisharief, Aurai and Ramgarh seats while former union minister Ram Vilas Paswan's LJP won Warisnagar, Araria and Bodh Gaya seats.