Police said that preliminary investigation suggested personal enemity as the cause behind the killing.
Yadav's supporters blocked roads and burnt tyres to protest the attack.
Yadav was a criminal before he took up politics and is locally known as 'bahubali' for the kind of power he wields in the area.
Three days ago, Bharatiya Janata Party (BJP) leader Ashok Jaiswal was shot dead in Patna's Danapur locality.