An ambulance has been called to a court in Russian-controlled Crimea after defendant Volodymyr Balukh, an imprisoned pro-Kyiv activist who has been on hunger strike for almost three months, felt unwell.

The Rozdolne district court judge adjourned Balukh's trial, which started in mid-May.

Balukh, who was convicted on a weapons-and-explosives-possession charge in August 2017, is now being tried for allegedly attacking a warden in a local detention center. He denies it.

Balukh was sentenced on the possession charge to three years and seven months in a penal facility, where convicts live close to a factory, farm, or other enterprise where they work as part of the punishment.

That sentence had been annulled by an appeals court and returned for additional investigation, but Balukh's retrial ended with the same verdict and sentence in January. Balukh contends the case against him was politically motivated.

The new case against Balukh was launched in March after the warden filed a lawsuit against him claiming that Balukh attacked him. Balukh started a hunger strike on March 19, protesting the new case against him.

Balukh was arrested in December 2016, after the Russian Federal Security Service (FSB) said explosives and 90 bullets were found in the attic of his home.

The search was conducted shortly after Balukh planted a Ukrainian flag in his yard and affixed a sign to his house that read Heavenly Hundred Street 18.

"Heavenly Hundred" is a term Ukrainians use for the dozens of people killed when security forces fired on protesters in Kyiv in February 2014, shortly before Russia-friendly President Viktor Yanukovych was driven from power.

After Yanukovych's ouster, Russia seized Crimea by sending in troops and staging a referendum dismissed as illegal by Ukraine, the United States, and about 100 other countries.

The Russian takeover badly damaged Moscow's relations with Kyiv and the West and resulted in the imposition of sanctions by the European Union, the United States, and several other countries.

Rights groups say Crimea residents who opposed Russia's takeover have faced discrimination and abuse at the hands of the Moscow-imposed authorities.

In 2017, the European Parliament called on Moscow to free more than 30 Ukrainian citizens who were in prison or under other conditions of restricted freedom in Russia, Crimea, and parts of eastern Ukraine that are controlled by Russia-backed separatists.