Police in home state of India's newly-inaugurated prime minister, Narendra Modi, have used tear gas to quell communal clashes.

Angry crowds set fire to several shops and vehicles and pelted stones at each other during the clashes in western Gujarat state's main city of Ahmedabad.

The clashes came as Hindu nationalist Modi, chief minister of Gujarat for 13 years, was sworn as prime minister on Monday after a landslide victory at elections as head of the right-wing Bharatiya Janata Party.

Ahmedabad joint police commissioner Manoj Shashidhar said officers fired tear gas to halt the violence which left four people injured, according to AFP news agency.

Shashidhar said that an investigation was under way into the clashes which appear to have started when two cars from the different communities crashed in an accident during a marriage procession.

"The incident flared up following a petty argument between people of two communities on Sunday night in Gomtipur area of the city. The situation was immediately brought under control," Shashidhar told AFP.

The incident escalated when mobs set property on fire, Ahmedabad chief fire officer MS Dastur told AFP.

"Some three shops, one mini-bus and a couple of two wheelers were burnt during the incident," Dastur said.

Modi has pledged national unity as he attempts to revive the faltering economy, but he remains tainted by anti-Muslim riots on his watch in Gujarat in 2002 that left at least 1,000 people, mainly Muslims, dead.

Modi has denied wrongdoing and a court investigation found he has no case to answer.

But some members of religious minorities fear a rise in communal tensions under a Modi government and warn they will be sidelined at the expense of the Hindu majority.

Source: AFP