Defence Minister Rajnath Singh on Wednesday told his Russian counterpart Sergei Shoigu that nuclear weapons should not be used by any side in the Ukraine war.

“The nuclear option should not be resorted to by any side as the prospect of the usage of nuclear or radiological weapons goes against the basic tenets of humanity,” Singh said, according to the defence ministry.

He also reiterated India’s stand on the Ukraine conflict and said that the path of dialogue and diplomacy must be pursued for an early resolution.

Singh remarks came after Shoigu spoke about his concerns related to the possible use of a “dirty bomb” – an explosive laced with radioactive material – by Ukraine.

Russia on Monday had alleged that Ukraine is planning to use a “dirty bomb” and blame it on Moscow to further escalate tensions, reported Reuters. However, it has not provided any evidence to support its claim.

Ukrainian President Volodymyr Zelenskyy had dismissed the claim by Russia and in turn, alleged that such a plan could be conspired by Moscow only, according to the Associated Press.

The United States had also rejected Russia’s assertions regarding the bomb, saying they are “transparently false allegations”. On Tuesday, President Joe Biden had said that Russia will be making an “incredibly serious mistake” if it were to use a tactical nuclear weapon against Ukraine.

Russia had launched an invasion of Ukraine on February 24. The Kremlin described its actions as a “special operation” to demilitarise and “de-Nazify” Ukraine. However, Kyiv and several Western nations have said that this is a baseless pretext for a war of choice by Putin.

According to the United Nations Human Rights Office, the conflict has killed at least 6,374 persons as of October 24 in Ukraine. On the Russian side, 5,937 soldiers have died, according to the country’s military.