WASHINGTON (Reuters) - Twelve inmates have been transferred from the U.S. military prison at Guantanamo Bay, Cuba, to Afghanistan, Yemen and the breakaway Somali enclave of Somaliland, the U.S. Justice Department said on Sunday.

Six Yemeni and four Afghan detainees were sent over the weekend to their home countries while two Somalis were transferred to regional authorities in Somaliland, an self-governing region within Somalia, the department said.

The transfers are the latest from the controversial prison President Barack Obama has pledged to close next month, but that deadline will likely be missed because of diplomatic and political hurdles.

With the latest moves, there are now 198 prisoners left at Guantanamo. Some of the remaining detainees will likely face trials in U.S. criminal or military courts while others are expected to be transferred abroad.

The transfers to Yemen are likely to revive concerns about moving individuals who were once considered terrorism suspects to a country where U.S. officials believe that al Qaeda elements are active.

Additionally, there have also been concerns about Al Qaeda activities in Somalia. In contrast, the breakaway region of Somaliland has enjoyed relative peace compared to the rest of Somalia since the Horn of Africa nation descended into chaos in 1991.

"These transfers were carried out under individual arrangements between the United States and relevant foreign authorities to ensure the transfers took place under appropriate security measures," the Justice Department said in a statement.