Advani refused a police request to move during a demonstration in the southern city of Bangalore against the arrest and jailing of Uma Bharti.

Advani and other Bharatiya Janata Party leaders had been held to prevent violence, police said.

They were later released without charge, police said.

Police in Bangalore, capital of southern Karnataka state, say more than 1,000 demonstrators were held at the rally.

Detentions without charge to prevent disturbances regularly occur in India.

Bharti of the Hindu nationalist BJP was sentenced to 14 days in custody in August over charges that she incited Hindu-Muslim violence 10 years ago.

Advani had agreed to head a week of demonstrations beginning yesterday against her detention.

"We will continue this peaceful agitation in the name of truth and justice for the next seven days," Advani told the rally before police intervened.

The demonstrations are scheduled to end with a public rally on 8 September to be addressed by former prime minister, Atal Behari Vajpayee.

The government in Karnataka agreed on Monday to drop all charges against Bharti, who resigned as chief minister of Madhya Pradesh state before she was arrested.

A court hearing yesterday at which she was expected to be released was postponed until Saturday.

Bharti, a firebrand Hindu nun, is one of the most charismatic politicians in the BJP.

She is accused of participating in a rally in Karnataka in 1994 which led to clashes between Hindus and Muslims after she unfurled the Indian flag over a prayer ground disputed by both communities.

Several people were killed in riots that followed.