The barrage, one of the fiercest of the three-year war, struck six Ukrainian territories, killing at least six people and injuring about 80, Ukrainian officials said.

It restated Moscow's demands that Ukraine become a neutral country - ruling out membership of NATO - and that it protect the rights of Russian speakers, make Russian an official language and enact a legal ban on glorification of Nazism. Ukraine rejects the Nazi charge as absurd and denies discriminating against Russian speakers.