Syrian state television broadcast a speech by opposition chief Ahmad Jarba at peace talks in Switzerland on Wednesday while at the same time showing footage of "terrorist crimes" in Syria.
The state broadcaster failed to identify Jarba as he began his speech at the conference in the Swiss town of Montreux.
In a split screen, it showed Jarba on the right, under the heading "Montreux, Switzerland," and on the left footage of death and destruction under the heading "Terrorist Crimes in Syria."
It ran quotes from Syrian Foreign Minister Walid Muallem, who spoke before Jarba, in a breaking news alert on the bottom of the screen as Jarba spoke.
State television used the same format when Turkey and Saudi Arabia's foreign ministers Ahmet Davutoglu and Saud al-Faisal spoke.
Both Turkey and Saudi are key backers of the rebels fighting to overthrow Assad.
While the two chief diplomats were shown on the right of the screen, the images on the left were of summary executions, bombings, pools of blood, destroyed buildings and dead bodies, including that of a child.
Later in the day, Syrian state news agency SANA published criticism of Saud's remarks.
"In his address, the minister of the terrorist Saud family delivered a series of lies and deceptions. He rambles and dreams of making Geneva II a conference that will serve his illusions," the agency said.
"His kingdom helps... fuel the crisis in Syria by supporting terrorism," SANA added, accusing the Saudi minister of being "disconnected from reality."
The two sides in Syria's nearly three-year-old conflict are meeting in Switzerland for the so-called Geneva 2 talks, a US-Russian initiative to try to end the violence.
More than 130,000 people have been killed since March 2011, when Syrians rose up in an initially peaceful protest movement against Assad that was met with a brutal crackdown, eventually igniting a full-scale war.
The Assad regime has long referred to all those seeking his ouster as "terrorists."