Two new satellite images show unidentified white shapes on top of Reactor 4 at the Zaporizhzhia nuclear plant.
There are five white shapes visible in the clearest of the images taken at 07.51am UTC (8.51am BST).
A second image taken at 10.16am UTC (11.16am BST) shows just three white shapes.
No white shapes can be seen in a third image which was taken in the hours before the other two photos, with Planet Labs marking the image as having been taken at 05.27am UTC (06.27am BST).
This could be due to a change in light but is inconclusive. It is not possible to confirm what the shapes are from the satellite images alone.
No changes can be seen on top of Reactor 3 in any of the satellite images sent to Sky News.
Speaking in a video on Tuesday, President Zelenskyy said: “Now we have information from our intelligence that the Russian troops have placed objects resembling explosives on the roof of several power units of the Zaporizhzhia nuclear power plant.
“Perhaps to simulate an attack on the plant. Perhaps they have some other scenario.”
He claimed the alleged devices were on top of reactors three and four.
Darya Dolzikova, from Royal United Services Institute’s (RUSI) proliferation and nuclear policy unit said: “It’s hard to judge from the imagery what the changes on the roofs show, including whether these are in any way related to the explosive devices that Ukrainian intelligence said may be present on reactor roofs at the ZNPP.
“But the sourcing of independent, reliable imagery is important and can help in verifying claims of what is happening at the ZNPP.
“However, the images, including the challenges related to verifying what they actually show, also once again stress the importance of granting the IAEA (International Atomic Energy Agency) all the access that it is asking for at the Zaporizhzhia nuclear power plant.”
The agency has requested extra access to the rooftops of two reactor units, as well as turbine halls and some parts of the cooling system at the plant to confirm the absence of explosives.
IAEA Director General Rafael Mariano Grossi said: “Our experts must be able to verify the facts on the ground. Their independent and objective reporting would help clarify the current situation at the site, which is crucial at a time like this.”
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