GENEVA (Reuters) - Syria and Russian airstrikes in rebel-held areas have killed 230 civilians in the past week in some of the conflict’s worst violence that may also constitute war crimes, the top United Nations human rights official said on Saturday.

Zeid Ra’ad al-Hussein, U.N. High Commissioner for Human Rights, said his office had received reports including video footage of possible use of “toxic agents” on Feb. 4 in the rebel-held town of Saraqeb, Idlib province.

“After seven years of paralysis in the (U.N.) Security Council, the situation in Syria is crying out to be referred to the International Criminal Court, as well as for a much more concerted effort by States to bring peace,” Zeid said in a statement.