(Reuters) -Ukrainian officials reported shelling around the capital Kyiv and the northern region of Chernihiv on Wednesday, despite a promise by Moscow to scale down military operations there.

       Russian forces were also shelling nearly all cities along the front line separating Ukrainian government-controlled territory from areas held by Russian-backed separatists in the eastern Donetsk region, the regional governor said, and heavy fighting was reported in the southern port city of Mariupol.

       Oleksiy Arestovych, an adviser to President Volodymyr Zelenskiy, said Russia was transferring forces from northern Ukraine to eastern areas to try to encircle Ukrainian troops there.

       He said Russia would keep some troops near Kyiv to try to prevent Ukrainian forces reinforcing the eastern front.

       "Although the Russians are withdrawing some troops from (around) Kyiv, they will still leave certain forces here (near Kyiv) to keep our troops here," Arestovych said in televised comments.

       Kyiv's deputy mayor, Mykola Povoroznyk, told national television the capital itself had not been shelled overnight.

       "The night passed relatively calmly, to the sounds of sirens and the sound of gunfire from battles around the city, but there was no shelling in the city itself" he said.

       The Chernihiv region's governor, Viacheslav Chaus, said he saw no let-up in Russian attacks.

       "Do we believe in it (the promise to reduce military activities)? Of course not," Chaus wrote on the Telegram messaging app.

       "The 'decreased activity' in the Chernihiv region was demonstrated by the enemy carrying out strikes on (the city of) Nizhyn, including air strikes, and all night long they hit (the city of) Chernihiv."

       The governor of the Khmelnitskyi region in western Ukraine said Russian forces had hit industrial facilities in the region in three strikes overnight.

       Governor Serhiy Hamaliy gave no details of the targets or the damage, but said fires had been "localised" and checks were being made to determine whether there were any casualties.

       Arestovych said street fighting in Mariupol was heavy and half the city had been taken by Russian forces.

       Vitaliy Kim, governor of the Mykolayiv region in southern Ukraine, said fighting also continued around occupied Kherson on the Black Sea and in the region as a whole.

       "We are not relaxing, we are working on strengthening our defence capability," Kim said.

       (Additonal reporting by Max Hunder and Matthias Williams, Editing by Timothy Heritage)