DAMASCUS, Syria -- The United Nations humanitarian chief said on Monday he is "horrified" by the attacks on civilians taking place in Syria, singling out in particular government airstrikes the previous day that killed nearly 100 people in a Damascus suburb.
The protracted conflict not only "severely affects" the lives of millions of people in Syria but also threatens the stability of the entire region, Stephen O'Brien said at a press conference in Damascus.
The stark warning comes amid a surge in violence as Syrian government troops, Islamic militants and rebels carried out attacks that killed and wounded dozens Monday, including in President Bashar Assad's coastal stronghold of Latakia.
"Attacks on civilians are unlawful, unacceptable and must stop," O'Brien said, speaking at the end of a three-day visit to Syria, during which he met senior officials and visited the central province of Homs.
Government air raids on Sunday killed at least 96 people in the eastern Damascus suburb of Douma, making it one of the deadliest single incidents since the crisis began in March 2011. The airstrikes hit a vegetable market in the suburb, which is a stronghold of the Islam Army rebel group.
Syria's conflict has killed more than 250,000 people, according to United Nations.
"I am particularly appalled by reports of airstrikes yesterday, causing scores of civilian deaths and hundreds injured, right in the centre of Douma," O'Brien said. "I am horrified by the total disrespect for civilian life in this conflict."
He appealed to all parties to protect civilians and respect international humanitarian law, and also expressed concerns for 4.6 million Syrian "stuck in hard-to-reach and besieged areas."
O'Brien also lambasted armed groups for cutting off water in Damascus, saying it was unacceptable to "use access to water and other services as a weapon of war."
Water cuts have been used before in the Syrian civil war, with Damascus and the northern city of Aleppo, Syria's largest city and former commercial centre, most affected.
In Washington, State Department spokesman John Kirby said the United States "condemns in the strongest possible terms the Assad regime's deadly airstrikes" on the Douma market.
"The Assad regime's brutal attacks on Syria's cities have killed thousands of people and destroyed schools, mosques, markets, and hospitals," Kirby said, adding that they "demonstrate the regime's disregard for human life."
U.N. special envoy Staffan de Mistura also condemned the Douma airstrikes.
"Hitting crowded civilian markets (and) killing almost one hundred of its own citizens by a government is unacceptable in any circumstances," de Mistura said, repeating calls for the warring sides to urgently start a dialogue toward a political solution.
Also Monday, the rebels in Damascus' wider eastern suburbs -- an area known as Eastern Ghouta -- imposed a curfew, fearing more government airstrikes and saying the curfew was imposed out of concern for civilian lives. The rebel statement said the curfew would go on until further notice. Douma is part of Eastern Ghouta.
The Britain-based Syrian Observatory for Human Rights reported 22 air raids on Eastern Ghouta on Monday, including seven in Douma. The Local Coordination Committees said Douma was hit with mortar shells.
Douma-based activist Baraa Abdul-Rahman said the streets there were empty and most people were staying indoors. "There is a situation of terror and fear in the town," he said via Skype.
In Turkey, the head of the main Western-backed opposition group, the Syrian National Coalition, blasted the government over Douma's air raids and urged the international community to help bring officials behind the "massacres and war crimes" to the International Criminal Court.
"Any talk about political and peaceful solution to the Syrian conflict in light of the daily and systematic regime massacres ... is meaningless," said the coalitions' Khaled Khoja.
Syria's Minister of Justice Najm El-Deen Ahmad, meanwhile, told The Associated Press that the authorities are not worried about any criminal charges against them at the ICC.
"It is the criminals who should be worried, and we have the evidence that could prove their involvement," he said, referring to the opposition.
Ahmad accused Turkey of setting up camps for training gunmen who later crossed into Syria to kill and plunder Syrian factories, and added that his ministry is preparing to file lawsuits against Turkey within a few months, both in local and international courts.
Syrian state TV reported that attackers shelled the government-held neighbourhood of Hamadaniyeh in Aleppo, killing 10 and wounding 17 on Monday. The TV also reported rebel shelling of the coastal city of Latakia, which killed six and wounded 19.
