Tanzania's second-biggest donor Denmark said it would withhold $10 million (R143.67mn) worth of aid money, citing concerns over human rights abuses and "unacceptable homophobic comments" made by a government official.

The decision came on the same day that the World Bank said it had scrapped a plan to loan Tanzania $300 million (R4309.98bn) after the country reaffirmed its policy of banning pregnant girls from school and recently made it a crime to question official statistics.

"I am very worried about the negative development in Tanzania, the latest being the completely unacceptable homophobic statements from a commissioner," Minister for Development Cooperation Ulla Tornaes said on Twitter on Wednesday.

Denmark will now withhold 65 million Danish crowns (R141.94mn) in aid to Tanzania, she added. Denmark provided 349 million crowns in foreign aid last year.

The comments in question were made by administrative chief of the capital Dar es Salaam, Paul Makonda, who earlier this month announced an anti-gay crackdown in the city, a spokeswoman for the Danish minister told Reuters.

Reuters was not able to reach Tanzanian government officials for immediate comment.

The foreign ministry has previously said Makonda's anti-gay campaign represented his own views and not the official government position.

However, President Magufuli's government has also been criticised by opposition politicians and international rights groups for what they say is growing authoritarianism and intolerance of dissent.

The government rejects the criticism.