UPDATE 3-Arrest of political leader sparks protests in Mumbai

(Updates with violence, details)

By Rina Chandran

MUMBAI Oct 21 (Reuters) - Police in western India arrested the head of a local right-wing party on Tuesday after attacks on migrant workers, sparking violent protests and the shutting of some businesses in the financial hub of Mumbai.

Raj Thackeray, who heads the small but vocal Maharashtra Navnirman Sena (MNS), was arrested in Maharashtra state on charges of rioting, a police spokesman said, and was brought to Mumbai. He will be held in jail for at least two weeks.

Police in Mumbai fired teargas shells and beat protesters with batons after the arrest of Thackeray, the nephew of Hindu nationalist leader Bal Thackeray, who founded the Shiv Sena party.

In 2005 Raj Thackeray deserted Shiv Sena, known for its anti-immigrant rhetoric and belief that Mumbai belongs to the ethnic Marathi community -- who originate from Maharashtra state of which Mumbai is capital -- to form the more militant MNS.

News channels ran pictures of non-Marathis being beaten in Mumbai's streets by MNS workers.

Analysts say the MNS is trying to revive the anti-immigrant rhetoric ahead of national and local elections due next year as it tries to hang on to its Marathi support base.

MNS supporters attacked north Indians seeking railway jobs in the city on Sunday, prompting calls for Thackeray's arrest and for the party to be banned.

Hundreds of MNS supporters shouted slogans, stopped taxis and autorickshaws and threw stones at police outside the Mumbai court where Thackeray was brought, the police spokesman said.

"There is some tension in Bandra and some suburbs, but the situation is generally under control," the spokesman said.

There were also reports of containers being attacked at the port and violence in the towns of Pune and Sholapur.

VIOLENCE SPREADS

The riots spread to the east Indian city of Patna, where hundreds of young men damaged a railway station, held up trains and clashed with the police to protest against the death of a migrant worker who had been attacked in Mumbai on Sunday.

Police in Patna fired in the air to disperse angry mobs who went on the rampage and chanted: "Punish the criminals. We can't tolerate any more." At least 12 people were injured.

Maharashtra Chief Minister Vilasrao Deshmukh, who had come under fire for dragging his feet on the arrest, said the detention showed "acts of intolerance will not be tolerated", and appealed to residents, many of whom stayed home, to remain calm.

There had been growing pressure on the state to check MNS, which has previously attacked migrant taxi drivers as well as workers in construction and manufacturing sites, driving many out of the state and causing delays to projects.

Thackeray was arrested briefly in February for inciting violence against migrant workers and MNS was recently reprimanded by a city court for forcing shops to display signs in the local Marathi language.

"As the Shiv Sena did in its heyday, MNS wants to combine economic grievances with regional pride and communal identity," a Times of India editorial said on Tuesday, calling for the Mumbai police to act against Thackeray.

Maharashtra, India's most industrialised state, has long been a magnet for job-seekers, particularly from Uttar Pradesh and Bihar, two of India's poorest states. Less than half of Mumbai's 17 million residents are from the state. (Editing by Bappa Majumdar and Alex Richardson)