NEW DELHI: Erstwhile Team Anna members Arvind Kejriwal and five others today surfaced in front of the residences of the Prime Minister and Congress and BJP party Presidents for a protest on the coal block allocation issue but were detained.

All the six - Kejriwal, Manish Sisodia, Gopal Rai, Kumar Vishas, Sanjay Singh and another person - were later released from custody after being detained for about an hour at the Mandir Marg police station where their supporters staged a protest and prevented police from taking them to Bawana.

Kejriwal and Gopal were picked up from outside Prime Minister Manmohan Singh's residence while Sisodia and Vishwas were detained from outside 10 Janpath, the residence of the Congress chief Sonia Gandhi. Sanjay Singh and another person were detained from outside BJP chief Nitin Gadkari's residence.

The activists had announced the gherao of the residences of these three leaders alleging that Congress and BJP were hand-in-glove in corruption and involved in the allocation of coal blocks.

Delhi police had warned against staging a 'gherao' at these places citing violation of prohibitory orders.

Though the activists had announced that they will gather at Jantar Mantar and march towards the residences of the leaders, Kejriwal and his aides took others by surprise and came to the protest venues where they were detained.

"What wrong are we doing? We are just sitting quietly on the footpath. At least we should be told why we are being detained," Kejriwal said. A spokesperson for the protesters said they did not violate prohibitory orders as only two persons had gathered at the spot.

"When Raj Thackeray takes thousands of his supporters without permission for a protest, police provide protection. What kind of politics is this?" he said.

Kejriwal said, "we will gherao again. We want to give message to Congress and BJP".

Meanwhile, six metro stations in central Delhi, which were earlier announced to be closed due to security concerns over the protest, will now remain open throughout the day.

A DMRC spokesman said the stations will remain open throughout the day after Delhi police revised their advisory.

Central Secretariat, Udyog Bhawan, Patel Chowk, Race Course, Jor Bagh and Khan Market stations falling near and around the residences of Singh and Gadkari were to remain closed from 8 am to 6 PM today.

Delhi Metro had taken the decision to close down the stations, five of which fall on the Gurgaon Line, after instructions from Delhi Police.