A combative nationalist MP has been wounded and two others killed in an explosion in Kiev, the sixth assassination attempt by a vehicle bomb in Ukraine in 15 months.

Ihor Mosiychuk, a member of the opposition Radical Party who has previously started fistfights in parliament and been imprisoned on terrorism and corruption allegations, was injured when a parked motor scooter blew up as he left a television station on Wednesday night.

His bodyguard Ruslan Kushnir, a 31-year-old police special operations officer, took the brunt of the blast and died on the way to the hospital. Mikhailo Mormil, a 36-year-old former lieutenant colonel in the interior ministry who was passing by, was also killed in the explosion, police said on Thursday.

Political analyst Vitaly Bala sustained injuries to his internal organs. Both he and Mr Mosiychuk underwent operations and were in stable condition.

Investigators said they are qualifying the explosion as a “terrorist attack” and that it could have been organised by Russian intelligence. Other possible motives were Mr Mosiychuk's political activities in Ukraine or a personal conflict, they said.

Mr Mosiychuk claimed on Thursday that Moscow had organised the hit and Ukrainians had executed it, promising to “personally carry out an investigation and hand down a verdict”.