The federal capital police claimed to have nailed 13 workers of the ruling PTI for storming Sindh House in Islamabad, 24NewsHD TV channel reported on Friday.
The arrested are accused of violating Section 144 and facing charges of trespassing, rioting and assault.
No activist has been released so far, a spokesperson said, adding that the law will take its course and investigation is on.
The ruling party workers barged into the Sindh House after staging a sit-in outside the building – right opposite the official residence of the chief justice of Pakistan.
PTI dissident lawmakers took refuge in the Sindh House till the National Assembly session on a no-confidence motion against Prime Minister Imran Khan.