 A dark patch could be seen on the Kremlin Senate building in Moscow on May 4 a day after an alleged overnight drone attack took place in the early hours of May 3. Moscow said on Thursday that the United States was behind what it says was a drone attack that aimed to kill President Vladimir Putin, while Moscow's forces fired more combat drones at Ukrainian cities including the capital Kiev. Putin's spokesman Dmitry Peskov, without providing evidence, said Ukraine had acted on U.S. orders with the alleged drone attack on the Kremlin citadel on Wednesday. The dark patch on the roof appeared to be scorch marks left in the wake of the alleged attack, but Reuters could not independently verify this. White House national security spokesman John Kirby said Peskov was just lying and said the United States neither encouraged nor enabled Ukraine to strike outside its borders. He added it was still unclear what had happened at the Kremlin.