Police authorities in Somalia's breakaway region of Somaliland are questioning two foreigners who were arrested in the region of Sanaag on Saturday, sources said.
The two men - one from Yemen, the other from China - were arrested alongside four Somalis in the port town of Las Korey.
The two foreigners were transported to a police station near Erigavo, the provincial capital of Sanaag, Somaliland Defense Minister Abdullahi Ali Ibrahim told reporters.
The group of men were caught with equipment and actual mineral samples, Mr. Ibrahim told a VOA Somali Service interview.
The four Somali men who were accompanying the foreigners have since been released, with officials saying the men hail from the neighboring sub-state of Puntland.
But Somaliland authorities accuse the Yemeni and Chinese nationals of entering their territory "illegally."
According to Somaliland media reports, the two foreigners are suspected of collecting mineral samples for a yet-unknown foreign company.
Somaliland investigators are questioning the foreigners in a bid to find out the purpose of their secret visit and the name of their employer, a police source said.
Puntland government officials have issued conflicting responses to the arrests.
Abdullahi Said Samatar, Puntland's security minister, told the BBC Somali Service that Somaliland police had detained "a group of fishermen," including the Yemeni and the Chinese national.
But Jama Hersi Farah, Puntland's state minister for securty, told the VOA Somali radio program that the men are suspected of "bringing weapons" into Puntland.
He indicated that the group of six men fled away from Puntland security forces, but were later arrested by Somaliland police in Las Korey.
Mr. Farah categorically dismissed Somaliland's claims that the men were collecting mineral samples from the region.
In recent months, northern Somalia - which is composed of Somaliland and Puntland - has been of increasing interest to foreign companies intending to exploit the region's rumored natural resources wealth.
In Puntland, a Canadian oil company has set up an operations camp in a remote town in May, although a recent report published by Garowe Online indicates that all foreign oil workers have been evacuated from the camp due to security-related reasons.
The government of Puntland has angrily denied the report in a press release issued on the government's official Web site.