"We were just standing with national flag and singing the national anthem," Yogendra Yadav said.
Politician-activist Yogendra Yadav and lawyer Prashant Bhushan were stopped by the police as they were marching towards the Rajghat to mark Mahatma Gandhi's death anniversary on Thursday.
Protestors from various locations were also going to the Rajghat, where they had planned to form a human chain against the Citizenship Amendment Act (CAA).
"Prashant Bhushan, myself and about 50 protesters have been detained from Delhi Gate. We were just standing with national flag and singing the national anthem. Police confirmed: no 144 in force, served us no order. Yet dragged and pushed into bus. Being taken to unknown destination," Mr Yadav tweeted in the evening.
Those who still managed to reach Rajghat formed a human chain and observed a one-minute silence at 5.17 pm, the time when Mahatma Gandhi was shot dead.
Holding a banner that read "No NRC, No CAA and No NPR", they paid tribute to Mahatma Gandhi and sang the national anthem.
CPI (M) leader Brinda Karat, who also participated in the human chain along with Sitaram Yechury, hit out at the Delhi Police for failing to file a First Information Report against Anurag Thakur and Parvesh Verma for their alleged incendiary remarks, and also "not taking" action in the Jamia incident.