Russian air defenses shot down 347 Ukrainian drones overnight, the Russian Defence Ministry said on Thursday, in what appeared to be a major attack after Moscow rejected a ceasefire offer from Kyiv. The drones were destroyed over 20 Russian regions, including Moscow, according to the Defence Ministry, in Ukraine's second-biggest aerial attack since Russia's invasion more than four years ago.

The attack came ahead of Russia's Victory Day celebrations, which mark the anniversary of the defeat of Nazi Germany in World War II. Russian authorities have declared a unilateral ceasefire in Ukraine for Friday and Saturday, but Ukrainian President Volodymyr Zelenskyy said Moscow disregarded the goodwill gesture and launched fresh attacks.

Ukraine's air defense shot down 92 of the 102 drones Russia launched overnight, the military said. Russian authorities have expressed concerns about possible Ukrainian attacks during the Victory Day celebrations, citing Kyiv's expanded long-range drone and missile capabilities.

The Russian government has announced additional security measures, including shutting down mobile internet access and text messaging services in Moscow on May 9, citing the need to ensure citizen safety. The traditional parade in Moscow will also not feature military equipment for the first time in nearly two decades.

The court and Russian authorities are yet to respond further to the attack, but the situation remains tense as the Victory Day celebrations approach. The US-led peace efforts are also expected to continue, although no breakthrough has been achieved so far.