Ghana's police have arrested at least 55 West Africans suspected of illegal gold mining, an immigration spokesman has told the BBC.
The arrests suggest that the police's focus has shifted away from Chinese miners to African miners, reports the BBC's Akwasi Sarpong in Accra.
More than 200 Chinese workers would be repatriated after their arrest last week, the spokesman said.
Ghanaian law prevents foreigners from working in small-scale gold mines.
Ghana is Africa's biggest gold producer after South Africa.
The raids are popular with many poor Ghanaians who feel that foreigners are taking jobs from them, our reporter says.
Immigration spokesman Francis Palmdeti told the BBC that of the 55 arrested, 51 were from Niger, three from Togo and one from Nigeria.
Identity checks were being done on three other detainees after they claimed they were Ghanaians, not Malians, as suspected, he said.
The raid shows that officials are determined to stop any non-Ghanaian from getting involved in artisanal mining, our correspondent says.
The suspects are being screened at an immigration detention centre in the capital, Accra.
The authorities plan to deport them, our reporter says.
Mr Palmdeti said the Chinese embassy in Accra had agreed to arrange flights for the repatriation of 202 Chinese workers arrested last week in raids in four mineral-rich regions.
Most of them have been freed on bail after the embassy gave an undertaking that they would not remain in Ghana illegally, he added.
Nearly 140 of the Chinese have also paid a fine of $1,000 (£640) each for illegally working in Ghana, Mr Palmdeti said.
Some of the foreigners work for local companies, our correspondent says.
At least one of these companies, Honsol Mining, is at loggerheads with the government over the deportations.
It insists that all its workers have valid permits, and alleges that members of the security forces have stolen goal during raids on its property this year, our correspondent says.
In October last year, a Chinese boy was killed during a security crackdown on illegal mining.
About 100 Chinese nationals were also detained over illegal mining the same month.