UNITED NATIONS - UN Secretary-General Antonio Guterres on Saturday voiced concern over civilian casualties and the destruction of media offices in Gaza by Israel, said his spokesman Stephane Dujarric.

The secretary-general is dismayed by the increasing number of civilian casualties, including the death of 10 members of the same family, as a result of an Israeli airstrike on Friday night in the al-Shati camp in Gaza, said Dujarric in a statement.

The secretary-general is also deeply disturbed by the destruction by an Israeli airstrike on Saturday of a high-rise building in Gaza City that housed the offices of several international media organizations as well as residential apartments, said the statement.

Guterres reminds all sides that any indiscriminate targeting of civilians and media structures violates international law and must be avoided at all costs, it said.

The 12-story al-Jalaa Building, where the offices of the Associated Press, Al-Jazeera and other media outlets are located, was leveled in an Israeli airstrike. Israel claimed the building housed Hamas military intelligence elements.