Security has been tightened in and around the southern Indian state of Karnataka where the body of a kidnapped former minister was found on Sunday.

Hannur Nagappa had been kidnapped in August by India's most wanted bandit, Veerappan.

On hearing the news of his death, hundreds of the former state agriculture minister's supporters attacked buses and vehicles in Chamarajnagar district, bordering the state of Tamil Nadu.

Police opened fire to disperse protestors in Kamagere, Mr Nagappa's home town, where they had been targeted with stones and knives.

Karnataka and Tamil Nadu police have launched a renewed search for Veerappan, and discussions for a new joint strategy are taking place.

A state funeral will take place later on Monday for Mr Nagappa in Kamagere.

Precautions

Trains and buses have also been cancelled between Tamil Nadu and Karnataka as a precaution, and some reports of attacks of vehicles registered in Tamil Nadu have come in from border districts of Karnataka.

Jayalalitha: Denied police involved in shootout

All government offices, schools and colleges were closed in Karnataka on Monday in mourning.

Karnataka's Director General of Police, T Madiyal, told the BBC that the border districts of Chamarajnagar, Mandya and Mysore were on high alert.

The BBC's Sampath Kumar in Tamil Nadu says that the fact that Veerappan is Tamil could be enough to trigger riots between the relatively large population of Tamils living in Karnataka and the state's majority Kannada-speaking community.

Relations between the two states are already strained due to a dispute over the sharing of Cauvery River waters.

And Veerappan's suggestion that Mr Nagappa had been killed by a bullet from the Tamil Nadu police could make matters even worse.

Mr Nagappa was found dead on Sunday, hours after Veerappan had released an audiotape saying he had abandoned his hostage after a gunbattle with Tamil Nadu police in which the former minister was shot.

Police involvement

The Tamil Nadu state government deny their forces were involved in a shootout.

Authorities said a bullet wound had been found on Mr Nagappa's chest but that the results of an autopsy were awaited for more details on the cause of his death.

Karnataka Chief Minister SM Krishna said that that an emergency cabinet meeting would be held on Monday evening to consider asking India's Central Bureau of Investigation to investigate Mr Nagappa's death.

India's Deputy Prime Minister, LK Advani, demanded joint action by the state governments of Tamil Nadu and Karnataka to hunt down the elusive brigand.

Joint operations had been reduced in recent months, but the two states have now stepped up joint operations to locate Veerappan, who has evaded capture for over 15 years.

Karnataka chief minister, SM Krishna, faces opposition calls for his resignation for not doing enough to hunt down Veerappan.

Mr Krishna described the death as "unfortunate" and said, "We tried to rescue Nagappa, but failed."