The UN human rights chief called on Syria's interim leadership on Sunday to intervene to prevent reported mass killings in coastal areas and bring the perpetrators to account.
"The caretaker authorities' announcements of their intention to respect the law must be followed by swift actions to protect Syrians, including by taking all necessary measures to prevent any violations and abuses and achieve accountability when these occur," UN High Commissioner for Human Rights Volker Turk said in a statement.
Meanwhile, Germany also described as "shocking" reports that more than 1,000 people have been killed in coastal Syria in the worst clashes since the overthrow of Bashar al-Assad.
"The transitional government has a responsibility to prevent further attacks, to investigate the incidents and to hold those responsible to account," the German foreign ministry said in a statement.
"We strongly urge all sides to end the violence."