WASHINGTON: The United States has released five detainees from its detention center at Guantanamo Bay, Cuba, including the first Yemeni detainee to be resettled since 2010, officials said on Thursday.

Three of the detainees were sent to the Republic of Georgia, the US military said in a statement, while two were sent to Slovakia.

The decision to release four Yemeni detainees and one Tunisian reduces the number of people held at Guantanamo to 143, part of a slow-moving effort by President Barack Obama's government to eventually close the facility.

More than half of the remaining detainees are from Yemen.

Obama promised to shut the detainee camp down during his 2008 presidential campaign, citing its damage to the US reputation around the world. But Obama has so far been unable to do so, in part because of resistance from Congress.

Read: Obama orders closure of Guantanamo

The Center for Constitutional Rights, which represented one of the Yemenis, Abd Al Hakim Ghalib Ahmad Alhag, criticised the Obama administration's refusal to release other Yemeni detainees.

It said 54 of the remaining 84 Yemeni detainees at Guantanamo had already been approved for transfer.

“As we welcome Mr. Alhag's resettlement, we are reminded that the remaining Yemeni men should be sent home or resettled without further delay,” Wells Dixon, CCR senior attorney, said in a statement.

Last week, the Republican congressman who heads the House Armed Services Committee, Representative Buck McKeon, cited an increase in Pentagon notifications of upcoming transfers of detainees out of Guantanamo.

He did not quantify them but, in a sign of continued pressure from Congress to halt releases, called the remaining detainees “the worst of the worst” and pointed to concerns that former Guantanamo detainees might join Islamic State fighters who seized large parts of Syria and Iraq.

Also read: Guantanamo closure by 2016 ‘unrealistic’: commander

Obama has started a military campaign, including US-led air strikes, to combat the group.

“To continue these releases just as we have had to open a new front in the war on terror is unwise,” McKeon told Defense Secretary Chuck Hagel in the Nov. 13 hearing.