UN chief concerned that use of chemical weapons would become 'normalized'

UN Secretary-General Ban Ki-moon on Monday expressed alarm at "the weakening taboo" against using chemical weapons in Syria.

Ban said in a letter to the Security Council that he is gravely concerned that the use of chemical weapons could become "normalized in this or any conflict, present or future."

"It is imperative that those responsible for the use of chemical weapons should be held accountable," Ban wrote.