Zambian police on Tuesday questioned opposition leader Hakainde Hichilema, for allegedly fuelling attacks on Chinese nationals, in a sign of growing political tension in Zambia.

Hichilema of the United Party for National Development (UPND) party, was last year detained for four months, for alleged treason in a case that many critics said was politically motivated.

Hichilema has repeatedly challenged the result of the 2016 election, which he lost to President Edgar Lungu.

Charity Katanga, the police chief of Copperbelt province, said Hichilema was questioned after alleging that the government had sold a state-run timber company to Chinese interests, prompting street protests in Zambia's second city Kitwe.

Some Chinese businesses were looted in the protests, as well as scores of protesters arrested.

Anti-Chinese sentiment in Zambia has grown over lucrative contracts, being awarded to China and government borrowing from Beijing.