U.N. chief Ban Ki-moon on Friday told Syria's prime minister in Tehran on Friday that fighting must stop in Syria "with the primary responsibility resting on the government to halt its use of heavy weapons."

In the meeting with Syrian Prime Minister Wael al-Halaqi and Foreign Minister Walid Muallem, Ban said he set out "my demands for all sides to cease all forms of violence," with Damascus bearing the greatest responsibility.

Iranian President Mahmoud Ahmadinejad urged Palestinian president Mahmoud Abbas to rally divided groups of Palestinians together to "free their land," according to his official website on Friday.

"All Palestinian groups should be united, because then they will have more chance of freeing their land," Ahmadinejad told Abbas, who was making his first visit to Tehran to participate in a two-day Non-Aligned Movement summit.

German Chancellor Angela Merkel has urged Israeli Prime Minister Benjamin Netanyahu not to order a military strike against Iranian nuclear sites, the newspaper Haaretz reported on Friday.

The article, citing an Israeli official on condition of anonymity, said Merkel had called Netanyahu 10 days ago amid a wave of reports of an imminent Israeli attack, to give a "clear message as to her opposition" to such action.

The United States and Israel are responsible for the conflict scorching Syria by "flooding weapons" to rebels there, the supreme leader of Iran -- the main ally of Syria's regime -- said on Friday, according to his official website.

"The main and behind-the-scenes operators behind the painful issues in Syria are America and the Zionist regime," Ayatollah Ali Khamenei said in a meeting with Syrian Prime Minister Wael al-Halaqi on the sidelines of a Non-Aligned Movement summit in Tehran.

U.N. chief Ban Ki-moon has called on Iran to free all its political prisoners, in a speech obtained by Agence France Presse on Friday and delivered in Tehran on the sidelines of a Non-Aligned Movement summit.

"I have urged the authorities during my visit this time to release opposition leaders, human rights defenders, journalists and social activists to create the conditions for free expression and open debate," Ban said, according to the text of the address delivered late Thursday to an Iranian diplomats' college.

Israeli security forces evacuated and demolished two dwellings in the wildcat settlement of Ramat Migron during the night, a police spokeswoman said Friday.

This comes ahead of the planned evacuation of nearby Migron, the largest wildcat settlement in the occupied West Bank.

Turkey will keep up its diplomatic efforts to protect refugees within the Syrian territory, despite the lack of an agreement at the U.N. Security Council, a Turkish diplomat told Agence France Presse Friday.

"We will continue to appeal to the international community to act," the diplomat said, speaking on condition of anonymity.

Fierce fighting rocked northern Syria on Friday as Ankara pressed its call for safe havens to be set up in the country to stem the refugee exodus and protesters demanded the fall of the regime.

U.N. chief Ban Ki-moon told Syria's premier at a summit in Tehran that Damascus must stop using heavy weapons in the conflict, and the International Committee of the Red Cross warned of a fast deteriorating humanitarian situation.

An American freelance journalist whose whereabouts in Syria were unknown for more than two weeks is being held by the Syrian government, his employers said Thursday.

The Washington Post, citing diplomatic sources, said that Austin Tice, 31, was detained near the Damascus suburb of Daraya, where activists say forces loyal to Syrian President Bashar Assad massacred hundreds of people last week.

A rocket fired from the Gaza Strip struck a house in southern Israel early on Friday, without causing any injuries, a police spokesman said.

"A rocket hit a house in the town of Sderot, causing damage to the roof. There were no injuries but a resident was hospitalized in a state of shock," said the spokesman, Luba Samri.