A rocket attack Saturday in the coastal Ukrainian city of Mariupol killed at least 10 people, reports said, citing local police officials. However, the administration at Mariupol, which is controlled by Kiev forces fighting the pro-Russian rebels, said that only three people died though many were injured.

The head of Donetsk regional police said that the firing was started by the rebels but the separatists reportedly denied the claims. Ukraine's Interior Ministry said, according to The Associated Press (AP), that the rockets had hit homes, setting them on fire, and nearby shops. The city has a population of 500,000 and is located between the rebel-held regions of eastern Ukraine and Crimea.

“Ten people have been killed as the result of the shelling of Mariupol's residential area in the streets of Kyivska, Olimpiyska, Pershoho Travnia by militants. The details are being specified," Viacheslav Abroskin, head of Donetsk's police department, said in a statement on Facebook, according to Interfax Ukraine, a local news agency. The statement added that 46 people had been injured in the attack.

Mariupol’s city council asked residents not to panic and clarified that the Ukrainian military forces will not withdraw from the city, as some rumors suggested, AP reported

"On the contrary, all units are on fully battle-ready. Security measures in the city have been strengthened," the council said in a statement, according to AP. 

The attack comes as Alexander Zakharchenko, pro-Russian rebel leader, said Friday that his troops will increase the offensive against government forces, and added that he did not want any truce with Ukraine, BBC reported

Clashes between Ukrainian military forces and pro-Russian rebels began after Crimea’s annexation by Russia last year, but the violence has intensified in the last nine days, during which 262 people were killed, the United Nations said, according to Reuters.