The Zimbabwe African National Union Patriotic Front annual meeting called for action against civic groups and non-governmental organizations associated with the United Nations, the BBC reported.
It urged the government to implement a constitutional amendment allowing the authorities to confiscate the passports of those who it sees as a threat.
Officials began putting that law into practice on Thursday when newspaper owner Trevor Ncube had his passport seized after he arrived at Bulawayo Airport on a flight from South Africa.
Ncube's newspapers, both in Zimbabwe and in South Africa, have been critical of Zimbabwean President Robert Mugabe's government.
On Friday, an official of the opposition Movement for Democratic Change, Paul Themba Nyathi, had his passport confiscated as he returned from a trip to South Africa.