United Nations chief Antonio Guterres said he was "deeply shocked".
Russia has been widely condemned after bombarding cities across Ukraine, including launching missile strikes on the centre of Kyiv for the first time.
The US said "brutal" attacks had hit non-military targets and promised ongoing military aid, including advanced air defence systems.
United Nations chief Antonio Guterres said he was "deeply shocked".
Vladimir Putin said the attacks were retaliation for Saturday's explosion on a key bridge linking Russia to Crimea.
Officials said at least 14 people were killed and scores more were injured.
