AUTHORITIES in India's Gujarat state have arrested at least 40 people after late-night clashes between Hindus and Muslims in the city of Vadodara.

They have also suspended mobile phone usage, the internet and bulk text messaging services for four days.

The trouble in Vadodara is thought to have started with a Facebook post that some Muslims thought offensive.

Crowds from the two religious communities pelted each other with stones and set several vehicles alight until police dispersed them using tear gas after days of tensions in the city.

Gujarat is the home state of Hindu nationalist Prime Minister Narendra Modi, who is currently in the US and is scheduled to meet President Barack Obama.

The state has a majority Hindu population and a history of religious conflict. At least 1,000 people, mostly Muslims, died in Gujarat in 2002 in violence between Hindus and Muslims. Mr Modi was chief minister of the state at the time.

Police said text messages and other social media had been used to spread messages about rioting and to inflame religious tensions.

Emboldened by Mr Modi's emphatic election victory in May, Hindu hardliners have been agitating in parts of India against religious minorities.

A prominent right-wing Hindu group has warned Muslims and Christians against taking part in the Hindu Navratri festival.

A senior state government official said yesterday: "Not many people are out due to fear of recurrence of violence.

"We are keeping a close eye on the situation."

Critics accused Mr Modi of allowing the 2002 riots to happen but courts found no evidence to indict him.