The United Nations human rights office on Saturday expressed concern over mass detentions carried out before and during protests in New Delhi, India.

"We are concerned by reports of mass detentions in India of demonstrators, protest leaders, members of civil society organisations, lawyers and journalists, before and during Saturday’s large-scale demonstrations in Delhi," it said in a statement.

The office also called on the authorities to ensure that the right to peaceful assembly is fully respected and fulfilled. "Restrictions on peaceful protests must meet strict tests of necessity and proportionality."

The Indian authorities should also ensure law enforcement forces exercise utmost restraint in response to peaceful protesters, consistent with the country’s democratic traditions and human rights obligations.

All those arbitrarily detained must be immediately and unconditionally released, the UN rights body said.

It also urged the authorities to engage in meaningful dialogue to address the broadly held concerns that were expressed.