Prime Minister of the self-proclaimed "Donetsk People's Republic" Alexander Zakharchenko attends a news conference in Donetsk August 11, 2014. Reuters/Sergei Karpukhin

Alexander Zakharchenko, the current head of the self-proclaimed Donetsk People's Republic, has announced plans to recruit 100,000 men as fighting between pro-Russian rebels and Ukrainian forces has intensified in eastern Ukraine.

According to Zakharchenko, the recruits would be voluntary and will have to go through a month-long combat training before they join three motorized brigades for counter-attack, BBC reported, citing a local news agency in Donetsk and Russia’s Interfax.

“It is a reserve force which will definitely be able to resist any attack," BBC quoted Zakharchenko as saying.

Meanwhile, the Ukrainian government also announced plans to increase the headcount of its forces in the country's east, while the U.S. is also said to be considering providing more weapons and military equipment to Ukraine to fight the rebels.

The latest developments have occurred at a time when heavy artillery attacks in Donetsk killed at least one civilian on Monday. Kiev’s military also said that five Ukrainian soldiers had been killed in clashes with rebels in the past 24 hours, Reuters reported. According to Kiev officials, separatist forces launched more than 100 attacks by weapons, rockets and tanks on Ukrainian positions and residential areas.

“As a result of these attacks and military clashes, Ukraine lost five service personnel and another 29 have been wounded,” Vyacheslav Seleznyov, a Ukrainian military spokesman, said.

Fighting between Ukrainian forces and rebels reportedly escalated around the town of Debaltseve in eastern Ukraine on Sunday, killing at least seven civilians in shelling attacks. Residents had to abandon the area due to heavy fighting, while many of the refugees were taken to Kiev-controlled Slaviansk from Debaltseve and other frontline towns.