Update: Congress President Rahul Gandhi was detained on Friday afternoon while protesting against the removal of CBI Director Alok Verma. He was taken to the Lodhi Colony police station in New Delhi.
Congress workers led by their president Rahul Gandhi took to the streets on Friday against the move to divest CBI Director Alok Verma of his powers and send him on leave, and to demand an apology from Prime Minister Narendra Modi.
The Congress, which marched from Dayal Singh College on Lodhi Road to the CBI headquarters about a kilometre away, has termed the move against Verma "illegal and unconstitutional".
Senior Congress leaders, including Ashok Gehlot, Ahmed Patel, Motilal Vora, Veerappa Moily and Anand Sharma, took part in the march that culminated in a demonstration ahead of the CBI headquarters.
Loktantrik Janata Dal leader Sharad Yadav, CPI leader D Raja and TMC's Nadimul Haque joined the protest.
Carrying placards against the prime minister, the protesters walked the distance with scores of police personnel maintaining vigil and camera crews jostling with each other to capture the moment.
One of the protesters was carrying a placard depicting the Central Bureau of Investigation in a cage.
Gandhi got on to a truck in front of the police barricades put up ahead of the CBI headquarters in the CGO complex to prevent the protesters from reaching the building.
Gehlot said the decision to remove CBI director Alok Verma was "illegal".
"The chief justice of India, the leader of the opposition and the prime minister can together take a decision to remove him, but not the prime minister alone," he told reporters.
"Our demand is to reinstate the CBI director. As per the law, he can be transferred only with the consent of the appointing authority (comprising Chief Justice of India, the prime minister and the leader of opposition). The prime minister should tender an apology to the nation for destroying the image of the premier investigating agency," Gehlot added.
The government has strongly defended its decision, saying it was "absolutely essential" to maintain the CBI's institutional integrity and the move was based on recommendations by the Central Vigilance Commissioner.
The Congress' protests in the national capital were replicated in other parts of the country.
State Congress leaders led demonstrations in their regions against what the Congress described as the "illegal, unconstitutional and illegitimate removal of the CBI director by the Modi-Shah duo that has shamed India and its premier investigative agency".
Alleging that the prime minister is experiencing 'Rafale-o-Phobia', the opposition party said the "demolition of the CBI" was prompted by fears that the director was going to conduct a probe into the fighter jet deal.
The government sent Verma and Special Director Rakesh Asthana, who have accused each other of corruption, on leave on Tuesday.
It also transferred several CBI officials and appointed M Nageswar Rao as the interim chief of the agency.
The Congress protest was held soon after the matter came up in the Supreme Court.
The apex court said former Supreme Court judge A K Patnaik will oversee a CVC inquiry into the allegations and counter allegations and the report has to be placed before it within two weeks.
It directed that interim CBI chief M Nageswara Rao shall not take any major policy decisions. Decisions taken by him since October 23 till date shall not be implemented, it said.
All decisions taken by Rao shall be placed before the apex court in a sealed cover.
The court sought a response from the CBI, the CVC and the Centre on Verma's plea challenging the government's decision to divest him of his duties.
A bench headed by Chief Justice Ranjan Gogoi posted the next date of hearing on November 12.