DAKAR, Senegal — The authorities in Ghana have conducted sweeping arrests of Chinese citizens in the nation's gold-mining regions, officials said Thursday, the latest sign of tensions between a sub-Saharan African nation and the global power that has become the continent's largest trading partner.

Police, immigration and intelligence officials have swooped down on Chinese gold miners in Ghana, Africa's second-largest gold producer, rounding up 169 Chinese citizens since June 1 and detaining them for deportation, according to immigration officials in the Ghanaian capital, Accra.

"It's an ongoing operation," said Michael Amoako-Atta, an immigration spokesman in Ghana, saying the Chinese had entered the country through "unapproved routes" or overstayed visas to engage in illegal mining. The government crackdown will continue, he added, "until we are clear that such kind of illegalities have ceased."

The small-scale mining activities of Chinese who have flooded into Ghana's gold-producing regions have stirred resentment in the West African nation, which is dependent on China for both trade and investment yet is also flexing its muscles as a new oil producer and one of the region's strongest economies.

The mines have left the countryside dotted with holes, polluted water supplies and raised accusations that the Chinese use Ghanaians as fronts in order to practice small-scale mining from which foreigners are otherwise barred. In October, a Chinese miner was shot by Ghanaian security forces, raising frictions.

In the capital on Thursday, a bus loaded with arrested Chinese miners was seen heading from the Ghanaian immigration headquarters to a court hearing. The headquarters' holding cell was full of arrested miners, many of whom clustered around the cell's solitary door to stare out at passers-by. The Chinese Embassy in Accra confirmed that its citizens were in detention and had not been seriously hurt, according to a statement posted on its Web site.

The arrests have become an intense subject of discussion among Chinese Internet users, with over one million posts on the topic on one popular microblog. Unverified photos circulating online purport to show Chinese people in Ghana with severe injuries. Whether those photos are accurate or not, they have stoked popular anger in China.

"The Chinese Embassy in Ghana has already dispatched personnel to mine sites to further verify relevant circumstances," Hong Lei, a Foreign Ministry spokesman, said Thursday at a regularly scheduled news conference in Beijing.

Authorities in Guangxi, the area of China that many of the miners call home, issued a statement on Thursday urging residents not to go to Ghana and offering miners plane tickets home. Many of the Chinese miners have entered Ghana illegally using tourist visas.

"If we all go back home, the economy of Shanglin will go backward at least 20 years," said a Chinese miner who had been hiding inside a Chinese company in Obuasi, one of Ghana's major gold-mining towns, for the past few weeks. "Who dares to be still operating the mine? We've all closed and been looking for places to hide."

"The Ghanaian authorities hunted us down in Chinese restaurants and hotels," said the miner, who would give only his last name, Li, out of fear for his safety. "Once they caught us, they took all our cash and cellphones. They were just like robbers, really violent."

But he was not pleased with the treatment he received from the Chinese government, either: "Our phone calls to the Chinese Embassy in Ghana always went unanswered."

Some of the world's largest mining companies have invested in Ghana, but unauthorized small-scale mining has been a persistent issue for the country and the Chinese workers there.

Last week, Ghana's minister for lands and natural resources warned that a crackdown on illegal miners was imminent, even as he was meeting with Chinese officials from Guangxi on the issue, according to The Ghanaian Chronicle, an Accra newspaper.

The arrests in Ghana are the latest reminder of continuing friction between China, which is investing heavily in a continent with plenty of natural resources, and Africans who routinely complain about Chinese disregard for local laws, customs and labor rights. Unions and workers have described unequal pay and brutal treatment, notably and recently in Chinese-run oil operations in Niger.

A 2009 report on Chinese investment practices on the continent, conducted by the African Labor Research Network, spoke of "labor relations and practices that are simply unacceptable." It said "trade unions across the continent have expressed deep concerns about the way they and their members are treated by Chinese companies," and referred to "the systematic violations of workers' rights" by the Chinese.

Chinese state-owned companies have been criticized in the past for ignoring the social and environmental impact of their projects when investing in resource-rich African countries. But the Chinese government has rejected criticisms that it is behaving like a colonial power.

China's president, Xi Jinping, who arrives in the United States on Friday to meet with President Obama, said during a visit to Tanzania in March that "China will intensify, not weaken, its efforts to expand relations with Africa."