INDISCRIMINATE rocket fire slammed into a market, schools, homes and shops Saturday in Ukraine’s southeastern city of Mariupol, killing at least 30 people, authorities said.

    The Ukrainian president called the blitz a terrorist attack and NATO and the U.S. demanded that Russia stop supporting the rebels.

    Ukrainian officials rushed to defend the strategically important port on the Sea of Azov, beefing up military positions with more equipment and sending in more forces.

    The separatists’ top leader declared that an offensive against Mariupol had begun — then later toned down his threats as the scale of the civilian casualties became clear.

    President Petro Poroshenko held an emergency meeting of his military officials and cut short a trip to Saudi Arabia to coordinate the government’s response.

    “The time has come to name their sponsors. The help given to militants, weapons deliveries, equipment and the training of manpower — is this not aiding terrorism?” Poroshenko said in a recorded statement.

    Russia insists it does not support the rebels, but Western military officials say the sheer number of heavy weapons under rebel control belies that claim.

    The rocket attacks came a day after the rebels rejected a peace deal and announced they were going on a multi-prong offensive against the government in Kiev to vastly increase their territory. The rebel stance has upended European attempts to mediate an end to the fighting in eastern Ukraine, which the U.N. says has killed nearly 5,100 people since April.

    The RIA Novosti news agency cited Ukrainian rebel leader Alexander Zakharchenko as saying an offensive had begun on Mariupol. Zakharchenko denied that his forces were responsible for Saturday’s carnage.(SD-Agencies)