A national guardsman was killed and nearly 90 others protecting Ukraine's parliament were wounded yesterday by grenades hurled from a crowd of nationalist protesters as lawmakers backed reforms to give more autonomy to rebel-held areas.

The violence, which Interior Minister Arsen Avakov blamed on the main nationalist party, and division in the pro-Western camp in parliament suggested President Petro Poroshenko faces an uphill battle to push through key parts of a faltering peace agreement reached in February for eastern Ukraine.

Poroshenko himself was set to address the nation later yesterday following the clashes outside parliament, where deputies loyal to him managed to push through a first reading of a "decentralisation" draft law - but only in the face of strong criticism from some of his political allies.

The violence came after 265 deputies voted in favour of the first reading of the bill, 39 more than that required to pass, at a boisterous session with many deputies shouting "Shame!" and rhythmically beating parliamentary benches.

Opponents of the bill said it played into Russia's hands and would lead ultimately to Ukraine losing control over the Donbass - the name given to the industrialised east, swathes of which are controlled by separatists now.

Elements in the crowd, many of whom carried banners from the nationalist Svoboda (Freedom) party, pelted black-helmeted national guardsmen with fire-crackers and smoke-bombs after the vote. Then, police said, grenades were thrown.

Interior Minister Arsen Avakov, in a tweet, said nearly 90 national guardsmen had been hurt, four of them with serious wounds to the eyes, stomach, neck and legs, by several explosive devices that were lobbed at them from crowds.