World powers supporting Syria's rebels decided on Saturday to take "secret steps" to change the balance on the battlefield, after the United States and others called for stepping up military aid to insurgents.

In their final communique, the ministers agreed to "provide urgently all the necessary materiel and equipment to the opposition on the ground, each country in its own way in order to enable them to counter brutal attacks by the regime and its allies and protect the Syrian people".

Hamas hanged two men accused of collaborating with Israel on Saturday, a statement from the interior ministry of the Islamist movement's government in Gaza said.

The ministry said that it had executed the two men in accordance "with what Palestinian law stipulates,” identifying the two men as "the collaborator with the occupation A.G., 49, and the collaborator H.K., 43."

A suicide bomber blew himself up in a Shiite mosque north of Baghdad on Saturday, the deadliest in a series of attacks that left 24 people dead nationwide days ahead of Shiite commemorations.

The unrest is the latest in a surge in nationwide violence which comes as the country grapples with months of protests by its Sunni Arab minority, tensions in a swathe of territory that Kurdish leaders want to incorporate into their autonomous region in the north and protracted political deadlock in Baghdad.

About a dozen U.S. fighter jets will be flying and conducting training operations in Jordan, poised to respond if needed to protect allies if the war in neighboring Syria spills over the border, U.S. administration officials said Friday.

The increased show of U.S. military might — which brings the total number of U.S. forces in Jordan to as many as 1,000 — should be seen as a signal to Syria that it must confine its 2-year-old civil war within its borders, officials said. The officials said it is meant to show that the U.S. is committed to its defense relationship with Jordan and that America intends to maintain a strong presence in the region.

Some 600 Russians and Europeans are fighting alongside Syrian rebels against President Bashar Assad's regime, Russian President Vladimir Putin said Friday, warning the West against arming the opposition.

"At least 600 people originating from Russia and Europe are fighting on the side of the Syria opposition," Putin told the Saint Petersburg Economic Forum.

Palestinian premier Rami Hamdallah on Friday withdrew an offer to quit a day after presenting it to President Mahmoud Abbas, an official said, just two weeks after the government took the oath.

Hamdallah emerged from a "positive" two-hour meeting with Abbas, a senior government official said, having made clear he wants his powers -- and those of his two deputies -- unequivocally defined to avoid further power squabbles.

The U.N. Security Council on Friday condemned what it said were arbitrary arrests and torture in Libya as it struggles with a transition to full democracy after the overthrow and death of Moammar Gadhafi.

In a statement approved by all 15 members, the council said thousands of people are being detained outside the authority of the state and without access to due process.

Secretary of State John Kerry headed to Qatar on Friday on a mission to coordinate with allies on the next steps in Syria as the United States considers how far to go on assisting rebels.

Kerry flew out of Washington on the start of a 12-day trip that will also include meetings in emerging U.S. partner India, an Asia regional conference in Brunei and his latest attempt to revive the Middle East peace process.

Soaring summer temperatures coupled with overcrowding, dwindling access to safe water and worsening hygiene are adding to the threats facing some four million children affected by the Syrian conflict, the United Nations said Friday.

"It is hot now, but it will only get hotter," Marixie Mercado, spokeswoman for the U.N.'s children fund, told reporters in Geneva, warning that temperatures in Syria and the surrounding region were expected to reach the mid-40s (up to 115 degrees Fahrenheit) in coming weeks.

Syrian rebels have recently received new weapons that could "change the course of the battle" against the Syrian regime, a spokesman for the Free Syrian Army told Agence France Presse on Friday.

"We've received quantities of new types of weapons, including some that we asked for and that we believe will change the course of the battle on the ground," FSA political and media coordinator Louay Muqdad said.