Syrian rebels have agreed to free 1,500 families in exchange for food and the release of jailed opponents of President Bashar Assad, a newspaper close to his regime said Monday.

The reported agreement involves the release of families held by rebels in Adra, a flashpoint town northeast of Damascus currently under siege by government troops.

Kuwait's Islamic Affairs Minister Nayef al-Ajmi, accused by a senior U.S. official of promoting jihad in Syria, said on Monday the Gulf state ruler has accepted his resignation.

"I thank the emir for accepting my resignation and understanding its reasons," Ajmi, who also holds the justice portfolio, said on his Twitter account without explaining the reasons.

A powerful jihadist group battling al-Qaida's affiliate in Syria has sharply criticized the global terror network's leader in a statement, rejecting his call for them to leave the war-ravaged country.

The audio recording, purportedly made by Islamic State of Iraq and the Levant spokesman Abu Mohammed al-Adnani, also urged Ayman al-Zawahiri to remove the leader of Al-Nusra Front, al-Qaida's affiliate in Syria.

Syria's presidential election campaign, launched at the weekend, has transformed the streets of Damascus into a glorification of incumbent Bashar Assad, who is expected to easily win the June 3 vote.

On the streets, parks and buildings of the city, barely a wall can be seen without a picture of the president, who is running for a third seven-year term as his troops battle rebels trying to oust him.

Israel's army on Sunday declared part of the Israeli-occupied Golan Heights a closed military zone, fearing battles on the Syrian side would spill over the ceasefire line.

An army spokeswoman told AFP the area around the Quneitra crossing was closed "for security reasons."

Campaigning began Sunday for Syria's June 3 presidential election expected to return Bashar Assad to power, as the regime marked a symbolic victory with the exit of rebels from Homs.

In Damascus, campaign posters lauding Assad hung on shopping streets and in public gardens, in the run-up to the country's first multi-candidate presidential vote.

Campaigning for Syria's June 3 presidential election expected to return Bashar Assad to power begins on Sunday, the Supreme Constitutional Court said.

It confirmed Saturday that the three candidates -- Assad, Maher Abdel Hafiz Hajjar and Hassan Abdullah al-Nuri -- can "launch their election campaign from Sunday," state news agency SANA reported.

Residents of Syria's second city Aleppo have been without water for a week because jihadists have cut supplies into rebel and regime-held areas, a monitoring group said Sunday.

The Syrian Observatory for Human Rights said the al-Qaida affiliate Al-Nusra Front had cut water supplies from a pump distributing to both the rebel-held east and government-held west of Aleppo.

More than 100,000 civilians have fled the eastern Syrian province of Deir Ezzor because of fierce clashes between rival jihadist groups, the Syrian Observatory for Human Rights said Saturday.

The British-based monitoring group also said the clashes between al-Qaida affiliate Al-Nusra Front and the rival Islamic State of Iraq and the Levant (ISIL) had killed 230 militants in the last 10 days.

Syrians streamed back into the ruins of the Old City of Homs on Saturday, picking through the remains of their homes and trying to come to terms with the destruction.

Thousands of people walked through the devastated streets of their former neighborhoods, some appearing shellshocked by the scale of the damage.