What will Putin do next? And other key questions

Emergency security measures remain in place in Moscow, after a rebellion by Wagner mercenaries that has shaken the position of the Russian president.

Many questions are still outstanding.

In a startling 24 hours, Vladimir Putin faced the greatest challenge to his authority since coming to power more than two decades ago. While the immediate risk seems contained, Russia experts say Putin does not emerge looking strong, but rather badly bruised.

Mr Putin's widely-noted loathing of betrayal appeared reflected in his stern national TV address on Saturday morning, where he accused Wagner leader Yevgeny Prigozhin of a "stab in the back" and treason.

Russia's president has not been seen in public since, and no new presidential address was being planned in the near future. In a pre-recorded interview on state TV on Sunday - which appeared to have been conducted before the rebellion - Mr Putin said he was confident in the progress of the war in Ukraine.

Anti-terror security measures are still in place in Moscow, but it is unclear whether President Putin is even in the Russian capital at the moment.

Some anticipate Mr Putin will lash out in some way, either militarily at Ukraine, or at those inside Russia who have been unsupportive.

Polish MEP Radek Sikorski told the BBC that the Russian leader would "probably purge those who he saw as wavering", meaning his regime will become "more authoritarian and more brutal at the same time".

The man behind the rebellion, Yevgeny Prigozhin, is a free man. Despite trying to topple the military leadership of Russia, the charge of armed mutiny against him has been dropped. But we don't know all the details of the agreement that was reached between the Kremlin and Wagner.

Russia analysts do not expect Prigozhin to disappear quietly into the night.

The mercenary leader - who has been a very vocal figurehead for tens of thousands of fighters in Ukraine - has also been an important figure for President Putin, operating in the shadows for a long time.

He has spent years doing dirty work for the Kremlin, from fighting in Syria to fighting in Ukraine in 2014, when it annexed Crimea.

But after challenging Mr Putin's authority - and some argue humiliating the Russian leader - questions about what guarantees he was given for his security, and his role going forward are still to be answered.

Observers are questioning how much control Belarusian leader Alexander Lukashenko will be able to exert over Prigozhin - if indeed he does go to Minsk - and, should Wagner forces follow him, what threat they will pose to Russia, Belarus and Ukraine.

Before this astonishing armed mutiny, tens of thousands of Wagner mercenaries were playing a key role in Mr Putin's war on Ukraine. But Wagner's days as an independent army were already coming to an end.

Prigozhin and his forces have been resisting pressure to absorb them into the Russian defence ministry - and disgust at that move is seen as a key factor in turning a long-running feud into rebellion.

But with the short-lived insurrection over - and Prigozhin now apparently heading to exile - many are asking what his fighters will do.

Charges have seemingly been dropped against those involved in the mutiny. Videos on social media have shown Wagner troops leaving the city of Rostov-on-Don, where they had taken control of military bases. The governor of Voronezh, which is half way between Rostov and Moscow, has said Wagner forces are also leaving his region.

However, it is unclear whether they will now simply co-operate and be integrated into the regular Russian military - or even if Russia's regular soldiers will now willingly serve alongside them.

And will they simply return to fighting in existing conflict zones in Ukraine, as Russian state media suggest? Some analysts have raised concerns that fighters could follow Prigozhin west if he does go to Belarus - the closest point from where Russia could attack the Ukrainian capital, Kyiv.

The Wagner group has been providing some of the most successful shock troops fighting in Ukraine, even though many of its fighters have been drawn from prisons, lured with the promise of freedom for frontline service. They were heavily involved in Russia's capture of the city of Bakhmut, for instance.

Russia claims the rebellion has had no impact on its Ukraine campaign so far.

However, Russian forces will no doubt have heard what's been going on and the news may be demoralising. Some suggest there could be in-fighting between rival units in the days to come, depending on what sort of aftershocks there are back in Russia following Saturday's events.

In Ukraine, in addition to a concern over risks that Russia may escalate its involvement, military leaders will be searching for opportunities from the instability across the border.

Kyiv's forces have launched a counter-offensive to reclaim territories captures by the occupiers and believe that unrest in Russia offers a "window of opportunity".

A former US ambassador to Ukraine, Bill Taylor, told the BBC Ukrainian forces were in "a good position" to exploit tactical weaknesses exposed by the sudden movement of Wagner fighters.

Ukraine in maps: Slow gains for counter-offensive

While Prigozhin's mutiny appeared to catch the Kremlin off guard, US spy agencies had already picked up signs he was planning to act and had briefed President Joe Biden along with key congressional leaders earlier this week, US media report.

US intelligence spotted that the mercenary group leader was massing weapons, ammunition and other equipment near the border with Russia, CNN reported.

According to the New York Times, President Biden spoke with the leaders of France, Germany and the UK because of concerns that Mr Putin's control of Russia's vast nuclear weapons arsenal could slip amid the chaos.

US spy chiefs had been tracking the deteriorating relationship between Prigozhin and Russian defence officials for months and intelligence had concluded it was a sign the war in Ukraine was going badly for both Wagner and the regular military, the paper says.

Meanwhile, the Washington Post says the US may have picked up that Prigozhin was planning something as early as mid-June.

A key trigger was a decree on 10 June by Russia's defence ministry ordering all volunteer detachments - like the Wagner Group - to sign contracts with the government, which would effectively be a takeover of Prigozhin's mercenary troops.

Officials told the paper "there were enough signals to be able to tell the leadership … that something was up" - but the exact nature of Prigozhin's plans weren't clear until shortly before the mutiny began.

President Putin was also told by his own intelligence that Prigozhin was plotting something, the paper reported. It is not clear precisely when he was told that, but it was "definitely more than 24 hours ago", the paper quoted a US official as saying on Saturday.

Mr Putin's address to the nation as the crisis was unfolding is being seen as a sign of how seriously he viewed the threat and the need to assert himself to the Russian public.

"Many inside the elite will personally blame Putin for the fact that everything went so far and that there was no proper reaction from the president in good time," a leading Russia analyst Tatiana Stanovaya wrote on Telegram. "Therefore, this whole story is also a blow to Putin's positions."

While it is hard to draw conclusions about overall Russian public opinion, the country's leaders would have been concerned by the sight of civilian onlookers applauding Wagner units in the city of Rostov.

As Wagner troops left the city they had effectively taken control of during their rebellion, they were greeted by an apparently supportive crowd who cheered, clapped and took photos.

However it is worth noting that some residents had seemingly rushed to leave the city by train on Saturday after Wagner arrived.