Indian police and striking autoworkers clashed for a second day Tuesday on the outskirts of New Delhi.
Employees from the Indian unit of Japan's Honda Motor Company and their supporters threw stones at police who used tear gas to break up the protests.
Monday, scores of workers and policemen were injured when police used batons to disperse the workers, who police say attacked them with canes and iron rods.
Indian Prime Minister Manmohan Singh expressed deep anguish over the violence and called for an independent investigation. Several opposition lawmakers in parliament accused police of "excesses" in handling the demonstrations.
Japan's ambassador to India, Yasukuni Enoki, warned that labor unrest could affect India's image as a destination for foreign investment.
Autoworkers were demonstrating for the reinstatement of 54 colleagues the motor company has suspended or dismissed.