An Islamist militant group that claimed responsibility for the kidnap and killing  of a Syrian television presenter has threatened more attacks on supporters of President Bashar al-Assad, the SITE monitoring group which tracks Jihadist websites said on Sunday.
The Syrian Observatory for Human Rights had said that Syrian state television presenter Mohammed al-Saeed, who was kidnapped from his home in mid-July, had been executed.
SITE said the al-Nusra Front stated in one of four communiques posted on Islamist forums on August 3 that it had kidnapped Saeed in Damascus province on July 19, and killed him after subjecting him to interrogation. 
It also threatened further attacks, including against Syrian journalists working for state media and those believed to be collaborating with the regime.
"The swords of the mujahideen will cut off their heads and purify the Levant from their obscenity," the post said.
It was not immediately possible to verify the claim from the group, which was unknown before it claimed responsibility for a series of bombings in Damascus and Aleppo that started in December.
Last month, al-Nusra claimed responsibility for a raid and bombing on June 27 of the Ikhbariya headquarters, a pro-government Syrian TV channel, in which seven people were killed.
In June, the al-Nusra Front claimed responsibility for the killing of 13 men whose bodies were found bound and shot in the city of Deir al-Zorr in eastern Syria on May 29.
On Saturday, gunmen kidnapped an employee at the Syrian ministry of education as he was on his way to Damascus.
Muhammed Ali Hussein was traveling into the city when armed men blocked his path, a source close to him said. It was not clear who he had been abducted by.
Also on Sunday British journalist John Cantlie, who was kidnapped by Jihadists in Syria last month, said his captors were foreign, including between 10 and 15 Brits.
"They were not from Syria: they were from anywhere but Syria.  They were from Bangladesh, they were from Pakistan, they were from the UK, they were from Chechnya," he said.
The Syrian government has long said it is fighting an international Islamist insurgency seeking to impose Islamic law in the country.