NEW DELHI — The fourth phase of India’s staggered national election Monday was marred by multiple clashes that injured at least seven people and led to security forces firing warning shots outside one polling station.

A junior minister in Prime Minister Narendra Modi’s Hindu nationalist party, Babul Supriyo, said his car was attacked by supporters of a rival party outside a polling station in West Bengal’s Asansol district as they tried to stop him from entering.

In West Bengal’s Dubrajpur area, security forces fired warning shots in the air at a group of voters who turned violent when stopped from carrying mobile phones into polling stations, the Press Trust of India news agency said.


Clashes between rival groups elsewhere in the state injured seven people, the agency reported.

They included a woman who was hit by a crude bomb that exploded outside a polling station, police said.

The Election Commission said police filed a case of trespass against Supriyo, the minister, for forcing his way into a polling station without authorities’ permission.

Modi’s Bharatiya Janata Party is facing a major test as it looks to govern for another five years after winning a clear majority in the 2014 election. The party suffered a setback in December when the opposition Congress party wrested power from it in three key state elections — Rajasthan, Madhya Pradesh and Chhattisgarh.

Rajasthan and Madhya Pradesh were among the nine states voting on Monday.

The remaining three phases of the election will be completed by May 19, and vote counting will begin May 23.

More than half of India’s 543 parliamentary constituencies had already voted in the election, which began April 11.

With 900 million of India’s 1.3 billion people registered to vote, the election is the world’s largest democratic exercise.