Tensions are high as Russia prepares to celebrate its most important secular holiday on Saturday, with fears about security amid the war with Ukraine and signs of domestic discontent casting a shadow over annual celebrations in Moscow’s Red Square.

A unilateral ceasefire in Ukraine that Russia announced for Friday and Saturday quickly unraveled. Moscow and Kyiv blamed each other for the continued fighting, just as they did when Ukraine’s own unilateral ceasefire swiftly collapsed earlier in the week.

The accusations reflect the deep-seated lack of trust between the two sides more than four years after Russia’s full-scale invasion of its neighbor. That has thwarted US-led diplomatic efforts to find a peace settlement.

Ukraine’s new drone and missile technology has helped it hit deep inside Russia frequently and accurately in recent months, especially major oil facilities.

Meanwhile, rumblings of unhappiness with some of the Kremlin’s wartime policies have put the spotlight on Russian president Vladimir Putin, who is due to make a speech on Saturday to mark Victory Day. It commemorates victory over Nazi Germany 81 years ago in the Second World War and has in the past provided an opportunity for fanfare and national fervour as well as showcasing Russia’s military might.

This year is different. The Russian Defence Ministry claimed on Friday that its forces in Ukraine “completely ceased combat operations and remained at their previously occupied lines and positions” from midnight, when Putin’s unilateral ceasefire came into force.

But it accused Ukrainian forces of continuing to strike Russian positions as well as civilian infrastructure in border areas of the Belgorod and the Kursk regions.

Air defences shot down 390 Ukrainian drones and six Neptune long-range guided missiles aimed at Russia after midnight, according to the ministry.

A Ukrainian drone strike hit the administrative building of the Southern Russia Air Navigation branch in Rostov-on-Don, forcing 13 airports in the south of the country to suspend operations, Russia’s Transport Ministry said.

Ukrainian leader Volodymyr Zelensky had a different story. Russian forces continued attacking on the front line overnight, he said, while Ukrainian air defence forces shot down 56 Russian drones.

“All this clearly shows that there was not even a pretence of a ceasefire attempt from the Russian side,” Mr Zelensky said.

Mr Zelensky also claimed on Friday another Ukrainian long-range strike on a Russian oil sector facility, this time in the Yaroslavl region, more than 700km (400 miles) from the border. He didn’t specify when the attack happened.

Russian officials have repeatedly warned that Moscow would take decisive action – including a potential mass strike on Kyiv – if Ukrainian attacks disrupt official events scheduled for Saturday.

“We have strengthened our focus on the possibility of retaliatory measures,” presidential aide Yuri Ushakov told journalists on Thursday.

Russia’s Foreign Ministry advised foreign embassies and international organisations located in Kyiv to evacuate their offices in case such a strike did take place, and the Defence Ministry urged civilians to evacuate, too.

Mr Zelensky, meanwhile, expressed surprise that foreign dignitaries would be going to Moscow for the commemorations.

Malaysia’s King Sultan Ibrahim Iskandar, Laos president Thongloun Sisoulith, and Belarus’ authoritarian leader Alexander Lukashenko were due in the Russian capital. Prime minister Robert Fico of Slovakia, a European Union member, was to meet with Putin and lay flowers at the Tomb of the Unknown Soldier memorial just outside the Kremlin walls but will stay away from the Red Square parade.

Putin, who has ruled Russia for more than 25 years, has used the USSR’s victory in the Second World War to rally support for him and the war in Ukraine, as well as to project Russia’s global clout.

That made it surprising that the traditional parade will take place without tanks, missiles and other military equipment, aside from war planes in a traditional flyover, for the first time in nearly two decades. Officials put the move down to the “current operational situation”, without elaborating.

Russia’s bigger and better-equipped army has been engaged in a slow, hard slog in Ukraine. The February 2022 invasion was supposed to deliver a quick win for the Kremlin.

Ukraine’s long-range attacks deep inside Russia are rattling the Kremlin. The attacks are targeting Russian oil production as well as manufacturing plants and military depots.

Some Russians are disgruntled about internet censorship and government control over online activities, including the blocking of the popular messaging app Telegram.

All mobile internet access and text messaging services will be restricted in Moscow on Saturday, according to the Ministry of Digital Development, Communications and Mass Media, which said that the drastic measures were to ensure public safety

The restrictions will apply to websites on the Russian government’s “white list”, a group of state-approved online services that are kept available during the country’s increasingly common connectivity blackouts. Home internet and wifi will be unaffected, authorities said.