The mob also vandalised his property and manhandled his family members before fleeing from the spot, he said.
The mob indulged in heavy stone-pelting and fired gunshots in the air, leaving many police personnel injured.
While the exact motive for the attack is not yet clear, Hakim Ali was reportedly attacked after an argument outside an ATM took an ugly turn on Saturday afternoon.
The move came days after the Supreme Court asked the government to enact a law to deal with such incidents, terming them as "horrendous acts of mobocracy".
The bench observed that vigilantism is not confined to any particular motive; it’s actually mob violence, which is a crime.
Responding to questions, CPI (M) general secreatry Sitaram Yechury said lynching and mob violence have "entered Bihar as soon as the BJP came to power there."