Russia has announced that it has begun the second phase of its invasion of Ukraine, targeting the eastern Donbas region. 

On Tuesday, Foreign Minister Sergey Lavrov announced that Moscow is beginning the next stage of its invasion of Ukraine with a full-scale offensive in the country’s east. 

“Another stage of this operation [in eastern Ukraine] is beginning and I am sure this will be a very important moment of this entire special operation”, Mr Lavrov said.

Mr Lavrov clarified that Russia will use only conventional weapons in response to a question about the possible use of nuclear arms in the war.

His comments follow speculation that Russia had engaged chemical warfare against Ukraine.

On Saturday, a Ukrainian mayor said that the “remains” of chemical weapons were found after Russian forces withdrew from the war-torn country’s northern Sumy region.

Yuriy Bova of Trostianets said officials found traces of Sarin, a nerve agent classified as one of the most toxic and rapidly acting known chemical warfare agents. 

A Ukrainian battalion also said Russia’s forces had used chemical weapons against soldiers in the southeastern city of Mariupol.

The Azov Regiment of the National Guard of Ukraine reported that three people were poisoned after an unknown chemical was dropped on troops by a drone.

Separatists have been in conflict with Ukrainian forces for about eight years in the Russian-speaking region and had declared Donetsk and Luhansk as independent republics.