Japan and Turkey joined the coordinated international protest of Syrian government oppression, Wednesday, by expelling Syrian diplomats from their borders.
Global leaders have expressed outrage over the May 25 Houla massacre, where forces back by Syrian President Bashar al-Assad are believed to have killed 108 victims execution-style at close range.
The United States, Britain, Canada, Australia, France, Germany, Italy, Spain and Bulgaria have all announced diplomatic expulsions as a result of the attacks.
Syria's state-run media denounced the international protests as "unprecedented hysteria" and an "escalation that aims to besiege Annan's plan and enflame a civil war."
Turkey, Syria's neighbor and a former close ally, has become one of the most outspoken critics of Assad's regime. The country closed its embassy in Damascus in March.
"It is out of the question to remain silent and without any reaction in the face of this action, which amounts to a crime against humanity," Turkey's ministry said in a statement Wednesday. "This grave crime against humanity by those who have attempted a massacre of civilians cannot go unpunished."
Meanwhile, Russia and China continue to oppose any United Nations intervention from the outside.
Wednesday, government forces continued to bombard rebel-held areas near Houla -- a day after U.N. Special Envoy Kofi Annan met with Assad in an attempt to salvage his proposed peace plan.
The U.N. Human Rights Council will meet in Geneva Friday to discuss a push by Britain and other EU countries for an independent investigation into the Houla killings.