Egypt's president says Syrian leader Bashar al-Assad must learn from “recent history” and step down before it is too late, while the Turkish prime minister said Syria has become a “terrorist state” carrying out massacres against its own people.

Egyptian President Mohamed Morsi told a meeting of the Arab League in Cairo Wednesday that a resolution to the crisis is an Arab responsibility, reiterating his call for the Syrian government to resign. He said the time has come in Syria for “change and not wasting time speaking of reform.”

Mr. Morsi also said a quartet of regional states proposed by Cairo to discuss the Syrian crisis would meet. The group includes Turkey, Saudi Arabia, Iran and Egypt.

In separate comments, Turkish Prime Minister Recep Tayyip Erdogan voiced further frustration at the lack of international consensus over the chaos in Syria. He told a meeting of his ruling AK party in Ankara that Turkey does not “have the luxury to remain indifferent” to what is happening in Syria.

Ankara initially cultivated good relations with Mr. Assad's government, but Mr. Erdogan has become one of the Syrian leader's harshest critics since the uprising against him began 17 months ago. Turkey, struggling to cope with an influx of around 80,000 Syrian refugees, has repeatedly pushed for a foreign-protected safe zone inside Syria, but the proposal has gained little international support.

Meanwhile, activists said Syrian forces killed at least 19 people, including seven children, when they shelled rebel-controlled areas of the commercial capital, Aleppo.

The Britain-based Syrian Observatory for Human Rights said Wednesday that 10 civilians were killed in the southern neighborhood of Bustan al-Qasr while a total of nine bodies, including those of the children, were found in the Marjeh and Hanano areas.

Other opposition groups said the death toll in the strategic northern city was as high as 43, including women and children. VOA cannot confirm events on the ground in Syria because the government severely restricts access for international journalists.