The government of Botswana has set down conditions for travel to the country by a UN human-rights spokesman in what critics say is part of a concerted campaign to cover up the state's shoddy treatment of the Bushmen, DPA reported. The government invoked a special clause of the constitution in requiring the UN special rapporteur on indigenous peoples, Mexican Rodolfo Stavenhagen, to obtain a visa to visit Botswana, the British- based human rights group Survival International said. The move resembles actions taken in March against a group of 17 foreign journalists, human rights activists and academics, who were marked out as needing to apply for a visa in advance of travelling to the southern African country. The government has explained the visa requirements saying it wants to be able "to offer assistance" to the targeted persons.