LUCKNOW, India (Reuters) - A one-month-old Hindu nationalist government won a crucial vote of confidence in India's most populous Uttar Pradesh state on Tuesday after opposition deputies walked out amid violence, witnesses said. The vote was carried through by the Hindu Bharatiya Janata Party (BJP) following the walk-out after several lawmakers were injured in violence that broke out in the assembly when it met to consider the vote. Trouble began when the leader of the Congress party, Pramod Tiwari, marched towards the chair of the state assembly speaker Kesri Nath Tripathi, witnesses said. Members of the Congress party, the centre-left Janata Dal and the socialist Samajwadi Party, raised slogans and were joined by lawmakers of the low-caste Bahujan Samaj Party (BSP), which withdrew critical support to the BJP on Sunday. The opposition lawmakers flung microphones and wooden planks towards the speaker's podium, witnesses said. BJP members hit back after remaining calm for a while, they said. The BJP and the BSP worked out an uneasy power-sharing-by-turns alliance in March in a hung assembly thrown up by inconclusive elections in October 1996. But the BSP, which ruled for six months until September, pulled the plug on BJP chief minister Kalyan Singh less than a month later.