- Russian drones had "for Moscow" and "for the Kremlin" written on them, Ukraine said.
- The messages suggest they were retaliation for an alleged Ukraine attack on the Kremlin.
Drones launched against Ukraine had "for Moscow" and "for the Kremlin" written on them, Ukraine's military said, suggesting they were meant as revenge, after Russia accused Ukraine of a drone attack on its capital.
Russian said on Wednesday that two drones were flown at the Kremlin, but were shot down. It claimed it was an assassination attempt against President Vladimir Putin.
Ukraine denied any involvement, and some experts say the alleged attack could have been staged by Russia itself.
Even so, Russian military forces appear to be retaliating.
The military chief of Ukraine's Kyiv region said on Thursday that Russia had launched its most intense attack on the Ukrainian capital so far this year.
And Ukraine's Operational Command South shared photos of two drones on Facebook, saying they were among 15 that Russia launched at the south Ukrainian port city of Odessa overnight on Wednesday.
The drones had "for Moscow" and "for the Kremlin," written on them, according to a translation by CNN.
Operational Command South said the messages showed the apparent "reason for the attack."
12 of the drones fired towards Odessa were destroyed by Ukraine's defenses, and three more hit dormitories of an educational institution in the city, Operational Command South said, adding that no one was hurt.
Ukraine's Air Force said 24 drones were fired by Russia on Wednesday night, and that it destroyed 18 of them.
Experts and Western officials have cast doubt on the Kremlin attack.
Washington DC-based think tank the Institute for the Study of War said in a Wednesday update that Russia "likely staged this attack in an attempt to bring the war home to a Russian domestic audience and set conditions for a wider societal mobilization."
It said there were "several indicators" to suggest it was staged by Russia, including the fact that the drones were able to get so far without being shot down, and the fact that the official Russian response was so coordinated compared to other attacks against Russia during the war.
Experts also told Insider that they were skeptical about Russia's account. Some said that the drones could have been sent by Ukraine as a warning or as proof of how it can penetrate Kremlin defenses, while others said Russia could have been behind it.
A senior UK defence source told Sky News that it appeared to have been staged by Russia.
"Anything is possible, but there is no benefit to Ukraine doing it, there is no military advantage, everyone knows Putin doesn't stay in the Kremlin and the motives are all really in Russia's favour," they said.