DUBAI (Reuters) - A militant group has claimed responsibility for the killing of 13 men whose bodies were found bound and shot in eastern Syria last month, killings condemned by United Nations monitors as "appalling and inexcusable".
Activists said at the time the dead men were army defectors killed by President Bashar al-Assad's forces, but the Al-Nusra Front, a militant group which has claimed several recent bombings, said the dead men were Syrian security officials.
The group said it had captured and interrogated a group of men in the eastern city of Deir al-Zor on May 29 and "justly" punished them with death, after they confessed to crimes.
"God enabled the lions of the east in Deir al-Zor ... to get the necks of a group of dogs from the security agencies and the thugs," read the statement posted on an Islamist web forum.
"Thirteen of those criminals were detained ... each of them faced his end in the worst killing and the very worst fate."
It was not possible to verify the claim from the group, which was unknown before it claimed responsibility for a series of bombings in Damascus and Aleppo, starting in December.
United Nations observers said last month 13 bodies had been discovered in Assukar, about 50 km (30 miles) east of Deir al-Zor. They had been tied up and executed.
A statement issued by the chief U.N. observer, Major-General Robert Mood, condemned the killings but did not accuse any side of perpetrating them.
(Reporting by Isabel Coles; Editing by Alison Williams)