WATCH: Footage Shows Grenade Being Thrown Into Crowd Outside Ukraine's Parliament

Ukraine's parliament voted on Monday for constitutional changes to give separatist-minded eastern regions a special status.

KIEV - A Ukrainian national guardsman was killed and nearly 90 others wounded by grenades hurled from a crowd of nationalist protesters on Monday as they were guarding parliament where lawmakers backed giving more autonomy to rebel-held areas.

The violence, which the government blamed on the main nationalist party, and division in the pro-Western camp in parliament suggested President Petro Poroshenko will struggle to push through key parts of a faltering peace agreement reached in February for eastern Ukraine.

Poroshenko sprang to the defence of the constitutional reforms 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.

Ukraine's parliament voted on Monday for constitutional changes to give separatist-minded eastern regions a special status - but divisions in the pro-Western camp and violent street protests suggested the changes would face a rougher ride to become law.

At a boisterous session, with many deputies shouting "shame" and rhythmically beating parliamentary benches, a total of 265 deputies voted in favor of the first reading of the bill, 39 more than that required to pass.

But many coalition allies, including former prime minister Yulia Tymoshenko, spoke against it and it is open to question whether Poroshenko will be able to whip up the necessary 300 votes for it to get through a second and final reading later this year.

Approval of legislation for special status for parts of Donetsk and Luhansk regions, which are largely controlled by Russian-backed separatists, is a key element of a peace agreement reached in Minsk, Belarus, in February.

Though a ceasefire is under pressure from sporadic shelling and shooting which government troops and rebels blame on each other, Western governments see the deal as holding out the best possible prospects for peace and are urging Ukraine to abide by the letter of the Minsk agreement.