A police chief in the occupied Ukrainian city of Melitopol, who defected to Russia after they seized the city, has been killed in an apparent partisan bombing.

Oleksandr Mishchenko died when an improvised device exploded at the entrance to the block where he lived, writes BBC.

There have recently been reports of heightened Ukrainian partisan activity in the region.

Melitopol's exiled mayor said the dead officer was a traitor.

The city is in Zaporizhzhia province, one of four regions that Russia claimed to have annexed last year following its invasion, despite only partially controlling them.

After Mariupol, Melitopol is the largest city on territory occupied by Russia since February 2022.

Russia's Interior Ministry said the explosion happened at 05:20 local time (02:20 GMT).

It added that two policemen were injured and hospitalised but subsequently one of them died.

A video of the scene showed a crater next to the apartment building and nearby cars with broken windows.

"The path of each collaborator is predictable: yesterday betrayal, today panic, tomorrow massacre," exiled Melitopol Mayor Ivan Fedorov wrote on his Telegram channel about the killing.

He said that before the invasion Mishchenko had been chief of the Priazovsky district police department, adding that he not only defected but also "tricked his employees into becoming traitors". It is unclear what Mr Fedorov meant by the allegation.

Volodymyr Rogov, a Russian-installed official in Zaporizhzhia region, said Mishchenko had several times been threatened by "terrorists" for "restoring peace to the region, preventing illegal acts and creating order in his native land".

Last year a number of Russian-installed officials were killed in attacks in occupied areas, including Zaporizhzhia region.

One of them was Oleh Boyko, the deputy mayor of the city of Berdyansk, who died along with his wife in September in an apparent assassination.

And a number of Russian-installed officials were killed in the southern city of Kherson last year by partisan activity ahead of the successful Ukrainian offensive that captured the city.