Russia said on Saturday it shot down 20 unmanned Ukrainian drones near the Crimean peninsula.
Fourteen were destroyed by air defence systems and six more were suppressed by electronic warfare, the Russian Defence Ministry said.
There were no casualties and no damage as a result of the attempted attack, the ministry said.
It was not clear what was targeted in the reported attacks on the Russian-annexed peninsula, Reuters said.
Sergei Kryuchkov, an adviser to the governor of Crimea, said that air defence systems were engaged in repelling air attack in different parts of the peninsula.
Crimea transport authorities said that traffic on the Crimean Bridge, which links the Black Sea peninsula with the Russian region of Krasnodar, was suspended for about two hours from 1.30am.
Drone attacks on Russian-controlled territories in Ukraine and inside Russia have increased since a drone was destroyed over the Kremlin in early May.
Ukraine almost never publicly claims responsibility for the attacks but has said destroying Russia's military infrastructure is crucial for Kyiv's counteroffensive.
In Moscow, officials said on Friday they had destroyed a drone aimed at the capital, the latest in a string of attacks.
A Ukrainian drone was destroyed over the western outskirts of Moscow, the Defence Ministry had said, adding there were no casualties or damage as a result of the incident.
In July, Ukrainian drone strikes on Crimea blew up an ammunition depot and damaged the bridge across the Kerch Strait linking the peninsula to Russia's mainland.