A stand-off in Ukraine has ended with security forces freeing 10 hostages from a bus in the city of Lutsk and detaining the gunman, after a bizarre intervention by the president.

Pictures showed the gunman lying on the ground after his arrest.

Just before the man's arrest, President Volodymyr Zelensky agreed to comply with his demand to post a short video, with the words: "Everyone should watch the 2005 film Earthlings."

All the hostages are unharmed.

The man has been named by police as Maksym Kryvosh, 44, who has previous convictions.

"Lutsk. Everyone is okay," Interior Minister Arsen Avakov tweeted (in Russian) following the end of the siege.

Mr Avakov was in Lutsk to lead negotiations with the gunman.
What was the president's role in the stand-off?

Explaining what had happened, President Zelensky said he had to keep pausing his meeting with his Swiss counterpart in order to be briefed on what was unfolding in Lutsk.

"There were unclear demands and it was hard to understand why it was happening. It took time to understand," he said in a video released by the presidential press service.

He said the gunman had been spoken to by a wide range of experts and although a special assault operation was discussed it was ruled out as too risky to the hostages.

President Zelensky said he then agreed to speak to the gunman and they had a 7-10 minute conversation during which it was agreed three people - a wounded person, a pregnant woman and a child - would be released in exchange for posting the video.

The president then posted a brief video on his Facebook page, referencing the film Earthlings. Narrated by Hollywood star Joaquin Phoenix, it is an animal rights documentary, which has won several minor festival awards. It shows, sometimes with hidden cameras, the practices of major world industries that rely on animals.

"After the video was published on social networks, we would release all the rest in half an hour," Mr Zelensky said. "Everything happened almost like that. In 30-40 minutes he released all hostages."

Mr Zelensky stressed his most important aim throughout the ordeal was to ensure there was no loss of life. "We are not fighting for popularity ratings, we are fighting for life. This is the primary value for me."
How did the siege develop?

The siege began at about 09:00 local time (06:00 GMT) on Tuesday. At one point the hostage-taker fired shots and threw explosives, which did not detonate.

His demands included one that senior politicians state publicly that he was a terrorist.

Officers of the counter-terrorism SBU security services surrounded the bus, and several hours of tense stand-off and negotiations ensued.

According to the prosecutor general's office, the gunman said he had placed an explosive device in a public place in the city that could be detonated remotely.

Police cordoned off the city centre and told residents not to leave their homes or offices.

It was not clear whether any device was found.

However, Mr Avakov later confirmed that Kryvosh had several functioning firearms and genuinely posed a threat.

"A lengthy prison sentence awaits him," he told journalists.

Officials said Kryvosh had previously spent around 10 years in prison on convictions including fraud and the illegal handling of weapons.