KYIV, Ukraine (AP) — Five people were injured in Russian rocket attacks Sunday in the centre of Kharkiv, Ukraine’s second-largest city, officials said.

Kharkiv regional governor Oleh Syniehubov said four people were injured when a Russian S-300 missile fell near an apartment block and another was hurt when a missile hit a higher-education building. Local media reports said the building hit was the National Academy for Urban Economy, about 700 metres from the city’s central square.

Meanwhile, heavy fighting continued in the Donetsk region of eastern Ukraine, one of four regions that Russia illegally annexed last year even though its forces do not fully control the region. Donetsk governor Pavlo Kyrylenko said five civilians were wounded in rocket attacks during the night in the city of Druzhkivka and that the town of Avdiivka and its outskirts were also fired on.

In the Black Sea port of Odesa, workers laboured to connect temporary generators shipped in to try to restore electricity. The city and surrounding area were plunged into darkness over the weekend following a large-scale network failure.

Grid operator Ukrenergo said that the failure involved equipment “repeatedly repaired” after Russia’s savage strikes on Ukraine’s energy grid, and that residents should brace themselves for lengthy blackouts.

As of Sunday afternoon, about 280,000 customers remained without power, said prime minister Denis Shmyhal.