ALEPPO - Russia has accused Belgium, a member of a US-led coalition fighting jihadists in Syria, of killing six civilians in air strikes in the Aleppo region but the claim was swiftly denied by Brussels.

"Six people were killed and four people injured to various degrees as a result of bombing that destroyed two homes" in the village of Hassajik in the Aleppo region early on Tuesday, the Russian defence ministry said in a statement.

"Two of Belgium's F-16s were identified at that time in the region," it said late Tuesday. "There were no Russian and Syrian air force planes in this region."

Belgian defence ministry spokeswoman Laurence Mortier denied the country's air force was active in the area at the time.

Moscow had announced on Tuesday that the Russian and Syrian air forces had stopped bombing Aleppo to pave the way for an eight-hour truce on Thursday.

Russian foreign ministry spokeswoman Maria Zakharova took a jab at the United States on Wednesday, calling on the State Department to release statements "strongly condemning strikes against civilian targets and the murder of civilians".

"I think that photographs of the dead will not be difficult to find to launch an appropriate campaign on CNN," she wrote on Facebook.

The brutal government offensive against rebel-held eastern Aleppo -- which has destroyed hospitals and other civilian infrastructure -- has plunged Syria into some of the worst violence of the five-year war that has claimed over 300,000 lives.

The West has accused Russia of potential war crimes over its bombing campaign in Aleppo in support of the regime offensive.

The US State Department voiced scepticism regarding Moscow's planned truce while welcoming a halt in the bombardments.

President Vladimir Putin is set to face Western pressure over the conflicts in Syria and Ukraine at international talks in Berlin on Wednesday as Russia comes under increasing criticism over its support for Damascus.