The advocacy group notes that, by its estimates, around 2,000 civilians were killed at the hands of the Syrian government of Bashar Assad since the uprising began in March.
Arab League Secretary-General Nabil al-Arabi said following a visit to Syria in July that the country was moving along the path toward reform. An Aug. 7 statement, however, called on Damascus to "immediately" stop attacks on civilians.
The official Syrian Arab News Agency denied claims that Syrian naval forces shelled the port city of Latakia. The U.S. State Department said it couldn't confirm Syrian naval activity though rights groups in the country said at least five people were killed by Syrian forces.
Human Rights Watch in a letter to Arabi called on the Arab League to urge Syria to end the violence.
"It should not shield a member state that has shot dead an estimated 2,000 of its citizens, the vast majority of whom were doing no more than peacefully exercising their right to protest," the letter read.
Syria's Arab neighbors in Jordan, Saudi Arabia and Turkey have all called for an end to the violence.
Turkish Foreign Minister Ahmet Davutoglu said in statements published by Turkish newspaper Today's Zaman that Ankara's patience with Damascus had run out.
"If these operations do not stop there will be nothing left to say about the steps that will be taken," he said without elaborating.