Nusra Front and Lebanese army exchange prisoners

Sixteen Lebanese prisoners of Syria's al-Qaeda affiliate were exchanged on Tuesday with 13 prisoners held by Lebanon at the border town of Arsal, shown live by the Al Jazeera Arabic TV channel.

The deal, brokered by Qatar, involved intensive on and off negotiations for over a year, after 30 security officers - policemen and soldiers - were captured in August 2014 in clashes when the al-Nusra Front and the Islamic State group briefly overran the army at Arsal.

The groups withdrew under a truce, but took the hostages with them.

Of the original number of hostages, 25 survived. Two were executed by Nusra Front. One of the bodies was turned over to Lebanese authorities earlier on Tuesday in the first stage of the swap deal.

IS also executed two other hostages, and a fifth died of injuries sustained in the fighting. 

The fate of the other 25 servicemen has been an ongoing crisis for the Lebanese state, which has entered negotiations multiple times to try to secure their release.

The deal consisted of Nusra Front freeing 16 Lebanese men - 13 policemen and three soldiers - in exchange for the release of 13 prisoners held by Lebanese authorities and the delivery of aid.

Live footage showed the 16 men arriving at an army checkpoint in the mountainous Jurud Arsal region of eastern Lebanon in four Red Cross vehicles.

The prisoners held by Lebanon are eight men and five women, including Saja al-Dulaimi, the ex-wife of IS's self-proclaimed caliph Abu Bakr al-Baghdadi. Saja al-Dulaimi is expected to stay in Lebanon with her infant daughter - who she gave birth to in captivity - before going to Turkey.

Nine detainees are still being held by IS, though it is unclear whether negotiations are ongoing for their release.

Lebanon's director general of security Major General Abbas Ibrahim supervised the exchange and later told reporters: "Our joy will not be complete until we are finished with the prisoners' issue that are held by IS."

"We are ready to negotiate with IS if we find one to talk to," he added.

The Lebanese government has allowed the prisoners it released to stay in the country if they didn't want to go back to the Nusra Front or IS. 

"Lebanon is a country of freedom and we welcome those who decided to stay," said Ibrahim.

For over a year, families of the hostages have camped out in downtown Beirut, refusing to budge until their sons were returned.

Relatives of the freed soldiers and police were ecstatic, weeping and ululating with joy as they watched the men, most of them sporting long hair and beards, board the Red Cross vehicles under the supervision of masked Nusra fighters.

But several said their joy was "incomplete" without the release of the rest of the men still held by IS.