This is happening simultaneously as Ukrainian forces continue to make marginal advances following the surprising land offensive that began last week.
The bridges are located in two towns near the border with Ukraine, according to Russian sources.
Geolocated images published on Friday show that one of the bridges has collapsed.
Maria Zakharova, spokesperson for the Russian Foreign Ministry, accuses Ukraine of using Western rockets in its attacks. She claims that the rockets "completely destroyed" the strategically important bridge and killed people who were helping with the evacuation of civilians.
For the first time, the Kursk region is being hit by Western rockets, likely American Himars, she says according to the Norwegian news agency NTB.
Russian military bloggers suspect that the destruction of the bridges may complicate Russian supply lines.
