It comes as Turkey warned the regime it would act to protect itself if a Syrian government crackdown on protesters threatened regional security and unleashed a tide of refugees on its borders.
Between 24 and 37 people were shot dead as protesters took the streets following Friday prayers and ahead of a general strike called for Sunday, according to a network of anti-government activists reporting events to a website based in Britain.
Ten were killed in Homs, the hub of the nine-month-old revolt, where televised footage showed demonstrators against President Bashar al-Assad chanting "Syria wants freedom" and Bashar is an enemy of humanity."
Peaceful demonstrations calling for reform began in Syria in March, inspired by the Arab Spring, but were met almost from the outset by lethal force.
If a government that is fighting its own people and creating refugees, is putting not only their own security at risk but also that of Turkey, then we have a responsibility and the authority to say to them: 'Enough!'" Davutoglu said.
Adding to the condemnation, a senior Saudi prince said Arab states would not turn a blind eye to violence in Syria. Former Saudi intelligence chief Prince Turki al-Faisal, seen as influential though no longer holding public office, told a conference in Vienna he believed the Arab League would not "sit back and allow the continued massacre of the Syrian people."
Activists say about 4,600 Syrians have been killed in nine months of protest and violent state suppression. Hundreds have fled over the border to Turkey which has established refugee camps.
Syrian state television Thursday aired confessions by "terrorists" bent on destabilizing the country by attacking security forces, killing and sabotage.
It said they admitted making and planting bombs but did not elaborate on their alleged political motive for such attacks.
Anti-government activists say three unarmed civilians have died for every security force member killed since March. They say Syrian interrogators use torture to obtain confessions.