A blast that rocked Syria's northwestern Idlib province on Thursday killed four people, state media said, though the cause had yet to be officially determined.

Residents told AFP they heard the sound of explosions on the western outskirts of the provincial capital, with a war monitor saying they came from a nearby base for foreign fighters.

Russia and Ukraine exchanged 84 prisoners of war from each side on Thursday, the Russian defense ministry said, in the latest swap which has seen hundreds of POWs released so far this year.

The ministry said on Telegram that the United Arab Emirates had mediated the exchange and that the released Russian service personnel were receiving "psychological and medical assistance".

Russian President Vladimir Putin on Thursday welcomed U.S. efforts to end the Ukraine conflict, speaking a day ahead of his summit with U.S. President Donald Trump.

"The U.S. administration... in my view is making quite energetic and sincere efforts to end the fighting," Putin told a meeting of top officials.

People are buying water by the truckload in Beirut as the state supply faces its worst shortages in years, with the leaky public sector struggling after record-low rainfall and local wells running dry.

A U.N. commission investigating sectarian bloodshed in Syria's Alawite heartland documented systematic violence at the hands of government forces and their allies, warning some of the acts could constitute war crimes, a report said Thursday.

The commission said it documented cases of "murder, torture and inhumane acts related to the treatment of the dead, widespread looting and burning of homes", leading to the mass displacement of civilians. "The violations included acts that likely amount to war crimes," it said.

Lebanese leaders firmly rejected any efforts at foreign interference during a visit by Iran's security chief Wednesday, with the prime minister saying Beirut would "tolerate neither tutelage nor diktat" after Tehran voiced opposition to plans to disarm Hezbollah.

The uncharacteristically blunt remarks hinted at a changed balance of power in a country where Iran has long wielded substantial influence by funding and arming Hezbollah.

A Hamas official said Wednesday that Israeli forces were making "aggressive" incursions into Gaza City, after the military approved the framework for a new offensive in the territory.

"The Israeli occupation forces continue to carry out aggressive incursions in Gaza City," Ismail Al-Thawabta, director general of the Hamas government media office in Gaza, told AFP.

U.S. President Donald Trump praised European leaders as "great people" on Wednesday ahead of talks in Berlin on ending the war in Ukraine.

Trump was to participate in a conference call with European leaders and Ukrainian President Volodymyr Zelensky ahead of his summit with Russia's Vladimir Putin in Alaska on Friday.

President Joseph Aoun told Iran's visiting security chief on Wednesday that he rejected any interference in the country's internal affairs, branding as "unconstructive" Iran's statements on plans to disarm Hezbollah.

Iran's top security chief vowed in Lebanon on Wednesday that his government would continue to provide support, after the Lebanese government ordered the army to devise a plan to disarm Tehran-backed Hezbollah.

Ali Larijani's trip to Lebanon comes after Iran expressed opposition to a government plan to disarm Hezbollah, which before a war with Israel last year was believed to be better armed than the Lebanese military.