Indian opposition leader Rahul Gandhi and his sister Priyanka were released by Delhi Police late on Friday evening, after over six hours of detention.

Rahul, Priyanka and other senior Congress leaders were detained by the cops during a protest by the country's principal opposition party against inflation and rising unemployment outside the grand old outfit's headquarters in Delhi this afternoon.

Around 1pm, Rahul, Priyanka and other senior leaders of the party were bundled into police jeeps and taken to Police Lines at Kingsway Camp as soon as they embarked on the protest. Around 7.15pm, all the leaders were released.

Read:Indian oppn leader Rahul Gandhi detained

"We're witnessing the death of democracy. What India has built brick by brick, starting almost a century ago, is being destroyed in front of your eyes. Anybody who stands against this idea of onset of dictatorship is viciously attacked, jailed, arrested and beaten up," Rahul said before his detention.

Earlier in the day, Rahul, his mother and Congress chief Sonia Gandhi, and several lawmakers of the party wore black clothes in Parliament to register their protest against rising prices, particularly of essential commodities, and unemployment.

A senior police officer told the local media that they were compelled to crack down on the protesters in the wake of the imposition of prohibitory orders by the authorities. "We have also not given them permission to hold any protest in Delhi," he said.

Rahul, son of Sonia and former Prime Minister Rajiv Gandhi, is seen by many as a future prime minister of India. Apart from his father, his grandmother Indira Gandhi and great grandfather Jawaharlal Nehru have all served as prime ministers of India.