The arrest, the first of a sitting chief minister, came hours after the Delhi high court refused to grant protection to the AAP national convenor from any coercive action by the agency.
Six persons were travelling to Punjab from Hemkund Sahib Yatra in a vehicle which was intercepted by Uttarakhand STF and local police following a tip-off.
The Delhi Police on Thursday detained 15 more people for their suspected involvement in the violence during the farmers' tractor parade in the national capital on January 26, officials said.