Russia has accused U.K. Foreign Secretary Boris Johnson of "Russophobic hysteria" after he accused the country of carrying out an attack on an aid convoy in Syria and called for demonstrations outside the Russian embassy in London.

Speaking in a U.K. parliamentary debate on Tuesday about the long-running civil war in Syria, Johnson said there was evidence that Russia – which is supporting the regime of President Bashir al Assad against rebel groups – was responsible for an attack on a United Nations aid convoy in Syria last month in which at least 20 people were killed.

"All the available evidence therefore points to Russian responsibility for the atrocity and I trust the UN board of inquiry will establish what happened," Johnson said.

The Russian Defense Ministry hit back on Wednesday, however, denying the allegation and accusing Johnson of "Russophobic hysteria."

"There were no Russian planes in the area of the aid convoy to Aleppo. That is a fact," ministry spokesman Igor Konashenkov said in a statement, Reuters reported on Wednesday.

In recent weeks, Russia and Syria have stepped up a bombing campaign in eastern Aleppo, killing hundreds of civilians in the process and attracting international condemnation with Russia accused of war crimes.

Johnson also called for demonstrations outside the Russian embassy in London in response to its involvement in the war in Syria, provoking a furore on social media site Twitter yesterday.

The U.K. foreign secretary added that thousands of people in parts of Aleppo were in dire need of humanitarian aid. He warned that eastern Aleppo – where the bombardment is focused - could be totally destroyed by the end of this year.

Russia and Syria have claimed they are targeting "terrorists" in the city but Johnson and said Russia risked becoming a "pariah nation" due to its role in the bombardment and that those involved should be investigated for war crimes.

"In the last two weeks at least 376 people, half of them children, have been killed, another 1,266 have been injured," he said, adding that there appeared to be "deliberate policy" of attacking hospitals, which was tantamount to a "war crime."

Johnson is not known for mincing his words, having made controversial remarks about numerous countries before becoming foreign secretary this year. But yesterday he took an unusual step by calling on people to take to the streets in protest.

"I would certainly like to see demonstrations outside the Russian embassy. Where is the Stop the War coalition?" he said.

The Russian Embassy in the U.K. tweeted its response, asking whether it was a new form of diplomacy.

But many accused the foreign secretary of being biased against Russia and drew attention to the U.K.'s close relationship to Saudi Arabia which has conducted a bombing campaign in neighboring Yemen to quell a Houthi uprising in the country.

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