UN Chief Ban Ki-moon voiced concern on Friday over the violence in Syrian city of Aleppo, urging the government and the opposition militants to stop the fight.

UN Chief Ban Ki-moon voiced concern on Friday over the violence in Syrian city of Aleppo, urging the government and the opposition militants to stop the fight.

"I'm seriously concerned by the escalating violence in Aleppo," Ban said during a visit to London for the Olympic Games.

"I urge the Syrian government to halt the offensive," he said, adding:  "The violence from both sides must stop for the sake of suffering civilians in Syria
Ban's warning came following a meeting with British Foreign Secretary William Hague.

Hague earlier said Aleppo operation could spark a humanitarian disaster.
"This utterly unacceptable escalation of the conflict could lead to a devastating loss of civilian life," Hague said in a statement.