A bomb killed two people during a pro-government march in the east Ukraine city of Kharkiv on Sunday, officials said, as Kiev’s army and rebels wrangled over a truce requiring them to pull back heavy weapons.

A bomb killed two people during a pro-government march in the east Ukraine city of Kharkiv on Sunday, officials said, as Kiev's army and rebels wrangled over a truce requiring them to pull back heavy weapons.

Tensions also rose around a new flashpoint -- the port city of Mariupol on the Azov Sea -- with Kiev accusing Russia of trying to wrest it away through the deployment of several tanks.

The Kharkiv blast tore through a "Dignity March" marking the one-year anniversary of the overthrow of the country's former pro-Kremlin president, one of several that took place across Ukraine.

Regional prosecutor Yuri Danilchenko described it as a "homemade bomb packed with shrapnel, put in a plastic bag and hidden in snow by the side of the road."

One of those killed was a police officer. Another 11 people were wounded.

An AFP journalist saw the two bodies lying on the ground covered with Ukrainian flags.

Kharkiv is located more than 200 kilometers (120 miles) from Ukraine's frontline, which continues to be contested in several areas despite a UN-backed truce meant to come into effect a week ago.