Russian opposition activist and blogger Alexei Navalny has been banned from leaving the country, he wrote on Twitter on Tuesday.

Navalny was due to fly to Strasbourg to hear the European Court of Human Rights’ decision on his case. "I arrived at the airport - I’m flying for the pronouncement of the ECHR’s decision - and the border guards took my passport ‘to carry out special checks,’" he wrote.

Later, the border guards said Navalny was not allowed to leave Russia. "There is a letter saying that the departure is prohibited, but there are no explanations for that," he noted.

Over the past six months, Navalny has been arrested several times for administrative offenses.

On October 2, Moscow’s Simonovsky Court sentenced Navalny to 20 days of administrative arrest for repeated calls to take part in rallies. The blogger was detained by police on September 29.

On September 24, Moscow’s Simonovsky Court ordered Navalny’s arrest for 20 days under Part 4 of Article 20.2 of the Administrative Offenses Code (violation of the established procedure for organizing or staging a meeting, rally or picket, resulting in harm to health or property).

On August 27, Moscow’s Tverskoy Court found Navalny guilty of an administrative offense under Part 8 of Article 20.2 of the Administrative Offenses Code (repeated violation of rules of organizing or holding a rally). Navalny was arrested for 30 days for staging an unauthorized rally in January 2018 in downtown Moscow. In February the court refused to consider the case twice, returning it to police to remedy violations.

On May 15, the Tverskoy District Court handed Navalny a 30-day arrest for arranging an unauthorized protest in Moscow on May 5. On the same day, he was sentenced to a 15-day detention penalty for disobeying police orders (since he had already been under arrest for 15 days).