A sacked Russian minister killed himself just hours after being fired by Vladimir Putin. An order published on the Kremlin website said Putin dismissed Transport Minister Roman Starovoyt on Monday, but no reason was given for his dismissal.

However, over the weekend, hundreds of flights were cancelled or delayed at Moscow's Sheremetyevo and St. Petersburg's Pulkovo airports, and thousands of travellers faced long waits. Other airports in western and central Russia also faced disruptions because of Ukrainian drone attacks.

Putin named Starovoyt's deputy, Andrey Nikitin, as acting transport minister. Nikitkin was the governor of Russia's Novgorod region until February. The announcement gave no reason for Starovoyt's dismissal. Kremlin spokesperson Dmitry Peskov refused to comment on it.

The news comes as Russia fired a barrage of more than 100 drones at civilian areas of Ukraine overnight, authorities said Monday, as Putin sacked his transportation chief after a weekend of travel chaos when airports grounded hundreds of flights during the busy vacation season due to the threat of attacks from Kyiv.

Zelensky said Saturday that Ukraine had signed deals with European allies and a leading US defence company to step up drone production, ensuring Kyiv receives "hundreds of thousands" more this year.

"Air defence is the main thing for protecting life," Zelenskyy wrote on Telegram on Monday. That includes developing and manufacturing interceptor drones that can stop Russia's long-range Shahed drones, he said. US President Donald Trump suggested he was going to give Patriot missile systems to Ukraine.

Extensive use of drones has also helped Ukraine compensate for its troop shortages on the front line.

One person was killed in the southern city of Odesa, 27 were injured in northeastern Kharkiv and falling drone debris caused damage in two districts of Kyiv, the capital, during night-time drone attacks, Ukrainian authorities said.