“The competent authorities at the Interior Ministry are seeking the culprits in order to bring them to justice,” the agency said.

Cartoonist Ali Ferzat, 60, said that four men abducted him while he returned home before dawn Thursday, and broke two fingers of his left hand, his right arm and damaged his left eye. Opposition activists have accused members of the security services and masked pro-regime militias of being behind the attack.

The US demanded Thursday that Assad’s government stop brutalizing peaceful opponents and in particular criticized its “targeted, brutal attack” on the cartoonist.

State Department spokeswoman Victoria Nuland had especially harsh words for the Assad regime regarding Ferzat, who is also a longtime human rights advocate, in a statement issued after the department had closed for the day.

“The regime’s thugs focused their attention on Ferzat’s hands, beating them furiously and breaking one of them — a clear message that he should stop drawing,” the statement said.

The statement came a week after President Barack Obama demanded explicitly that Assad resign because he had lost legitimacy as a ruler. That demand was in conjunction with similar moves by major US allies such as Britain, France, Germany and the European Union.

In her statement, Nuland said: “Many other moderate activists who oppose violence have been jailed for speaking out against the regime, including Walid Al-Buni, Nawaf Basheer, Georges Sabra, Mohammed Ghaliyoun and Abdullah Al-Khalil. Some have been held for months incommunicado.

“While making empty promises about dialogue with the Syrian people, the Assad regime continues to carry out brutal attacks against peaceful Syrians trying to exercise their universal right to free expression,” Nuland continued. “We demand that the Assad regime immediately stop its campaign of terror through torture, illegal imprisonment and murder.”