Russia rained cruise missiles on busy Ukrainian cities, knocking out power and heat in its most widespread air attacks since the start of the war.
Missiles tore into busy intersections, parks and tourist sites in the centre of the capital Kyiv on Monday.
Explosions were also reported in Lviv, Ternopil and Zhytomyr in western Ukraine, Dnipro and Kremenchuk in central Ukraine, Zaporizhzhia in the south and Kharkiv in the east. Ukrainian officials said at least 11 people were killed and scores injured, with swathes of the country left without power.
Thousands of residents raced to bomb shelters as air raid sirens rang out through the day. The barrage of dozens of cruise missiles fired from air, land and sea was the biggest wave of air strikes to hit locations away from the front line, at least since the initial volleys on the war's first day, 24 February.
President Vladimir Putin said he had ordered "massive" long range strikes after an attack on the bridge linking Russia to the annexed Crimean peninsula over the weekend and threatened more strikes in future if Ukraine hits Russian territory.
"To leave such acts without a response is simply impossible," he said, alleging other, unspecified attacks on Russian energy infrastructure.
Ukrainian President Volodymyr Zelensky said the Russian attacks were deliberately timed to kill people, as well as to knock out Ukraine's power grid. His prime minister said 11 major infrastructure targets were hit in eight regions, leaving swaths of the country with no electricity, water or heat.
"They are trying to destroy us and wipe us off the face of the earth," Zelensky said.
The body of a man in jeans lay in a street at a major Kyiv intersection, surrounded by flaming cars. In a park, a soldier cut through the clothes of a woman who lay in the grass to try to treat her wounds. Two other women were bleeding nearby.
Battlefield setbacks
The Kremlin was humiliated two days ago when a blast damaged Europe's longest bridge, which it had built after it seized Crimea in 2014. Ukraine, which views the bridge as a military target sustaining Russia's war effort, celebrated the blast without officially claiming responsibility.
With troops suffering weeks of setbacks on the battlefield, Russian authorities have been facing the first sustained public criticism at home of the war, with commentators on state television demanding ever tougher measures.
Ben Hodges, a former commander of US army forces in Europe, said the scale of the strikes suggested Russia's plan to escalate may have been drawn up before the bridge was attacked.
Ukrainian military intelligence said the attacks were ordered on 2 and 3 October. "The objects of critical civil infrastructure and the central areas of densely populated Ukrainian cities were identified as targets," it said.
Monday's strikes tore a huge crater next to a children's playground in one of central Kyiv's busiest parks. The remains of an apparent missile were buried, smoking in the mud.
More volleys of missiles struck the capital again later in the morning. Pedestrians huddled for shelter at the entrance of Metro stations and inside parking garages.
"This constitutes another unacceptable escalation of the war and, as always, civilians are paying the highest price," UN spokesman Stephane Dujarric said in a statement.
US Secretary of State Antony Blinken called the strikes "horrific" and reiterated US support for Ukraine.
By mid-morning, Ukraine's defence ministry said Russia had fired 81 cruise missiles, and Ukraine's air defences had shot down 43 of them. Russia's defence ministry said it had hit all its intended targets.
Security camera footage showed shrapnel and flames engulfing a glass-bottomed footbridge across a wooded valley in Kyiv's centre, one of its most popular tourist sites. One pedestrian could be seen running from the blast. Reuters later saw a crater below the bridge, damaged but still standing.
Zelensky said the strikes had two main targets: energy infrastructure and people.
"Such a time and such targets were specially chosen to cause as much damage as possible," he said in a video message filmed on a mobile phone on an empty central Kyiv street.
Prime Minister Denys Shmygal promised to restore utilities as quickly as possible. Foreign Minister Dmytro Kuleba tweeted: "Putin is a terrorist who talks with missiles."
Olena Somyk, 41, sheltered with her 6-year-old daughter, Daria, in an underground garage where hundreds of other people waited for the all-clear. She had reached Kyiv earlier in the war after fleeing through Russia and across Europe from the Russian-occupied southern city of Kherson.
"Really, I think they did this because they are bastards," said Somyk. Putin, she said, "is a small angry man, so we don't know what more to expect".
Belarus escalation
In another sign of possible escalation, Putin's closest ally, President Alexander Lukashenko of Belarus, said he had ordered troops to deploy jointly with Russian forces near Ukraine, which he accused of planning attacks on Belarus with its Western backers. He allowed Russia to use Belarus as a staging ground early in the war but has not sent in his troops.
Within Russia, the strikes were cheered by hawks. Ramzan Kadyrov, the staunchly pro-Kremlin leader of Russia's Chechnya region who had recently demanded that military commanders be sacked, wrote: "Now I am 100 percent satisfied with how the special military operation is being conducted."
"We warned you Zelensky, that Russia hasn't even got started yet, so stop complaining ... and run! Run away without looking back to the West."
Russia has faced several setbacks since the start of September, with Ukrainian forces bursting through front lines and recapturing territory.
Putin responded by ordering a mobilisation of hundreds of thousands of reservists, proclaiming the annexation of occupied territory and threatening repeatedly to use nuclear weapons.
- Reuters