The U.N. refugee agency said Tuesday it was poised to mount a massive aid operation for 500,000 Iraqis driven from their homes by jihadist rebels.

"In response to the deteriorating situation in northern Iraq, UNHCR is this week launching one of its largest aid pushes aimed at helping close to half a million people who have been forced to leave their homes," spokesman Adrian Edwards told reporters.

Four people were arrested over the killing of Lebanese journalist Mazen Diab in Jordan, the neighbouring country's Public Security announced on Saturday, noting that the murder was motivated by a personal dispute between the victim and one of the assailants.

Jordan's Public Security Directorate Media Center stated on Saturday that “the ambiguity surrounding the discovery of Diab's body has been unveiled, and four people were arrested for their involvement in committing the crime.”

Jordanian police on Friday announced that it has discovered the body of Lebanese journalist Mazen Diab at his house in the capital Amman.

"Security forces found the body of Diab tied with ropes inside his apartment,” Jordanian news agency ZAD said, noting that his house is located on Mecca Street in Amman.

The Organization of Islamic Cooperation (OIC) on Wednesday welcomed the nomination of Haidar al-Abadi as new prime minister of Iraq, though incumbent Nuri al-Maliki is clinging on to power.

Abadi has won broad international backing, from the United States, Saudi Arabia and Iran amongst other countries.

Jordan's King Abdullah II warned Sunday that Israel will only achieve security for its people through a peace settlement with the Palestinians leading to the establishment of their own state.

Doctors and aid agencies are trying to capitalize on a truce in Gaza to evacuate more wounded Palestinians for life-saving medical treatment in east Jerusalem, Israel and Jordan.

Advocacy group Human Rights Watch accused Jordan Thursday of refusing entry to, or forcibly deporting, Palestinian refugees escaping Syria in what it called a defiance of the country's international obligations.

In a report released in Amman, the New York-based group said Jordan has officially banned their entry since January 2013 and has forcibly deported more than 100, including women and children, who managed to enter the country since mid-2012.

Jordan has presented a new resolution on the Gaza crisis to the U.N. Security Council and hopes for action on the measure in the coming days, its ambassador said Tuesday.

The draft resolution backed by Arab countries calls for a lasting ceasefire between Hamas and Israel, as well as an international effort to rebuild Gaza after four weeks of fighting killed at least 1,867 Palestinians and 67 Israelis.

Jordan's national carrier on Saturday suspended flights to the Iraqi capital for security reasons, an airline official told Agence France Presse.

"Royal Jordanian suspended its flights to Baghdad today because of the security situation," said the source, speaking on condition of anonymity.

Thousands of Jordanians took to the streets of Amman and other cities Friday to support Hamas and condemn Israel's offensive in Gaza, where more than 800 Palestinians have been killed.

Around 2,000 people demonstrated in central Amman after Friday midday prayers, chanting: "We sacrifice our blood and souls for you, Gaza," in support of Hamas' armed wing the Ezzedine al-Qassam Brigades.