MOSCOW — A court in Chechnya on Monday ruled to keep a human rights activist in custody despite international criticism of his arrest.

The court in the central town of Shali extended Oyub Titiyev's arrest for another six months. Titiyev, the head of Chechnya's branch of Russian human rights group Memorial, has been in jail since his arrest in January on drug possession charges, which Memorial described as a sham. His trial is set to start next week.

The United States, the European Union and international rights groups have condemned Titiyev's arrest as part of official efforts to muzzle critical voices in Russia.

Chechnya's regional leader, Ramzan Kadyrov, rejected the criticism, saying Titiyev's arrest was in line with the law.

Memorial head Oleg Orlov and Svetlana Gannushkina, another prominent Russian rights defender, were briefly detained by police in Moscow when they picketed in Titiyev's support.