Amnesty International on Thursday called for an investigation into alleged abuses against detainees in Russia and Azerbaijan.

In the statement, Amnesty International’s Director for Eastern Europe and Central Asia, Marie Struthers said:

The authorities in both Russia and Azerbaijan have shown complete disregard for human dignity and open contempt for their human rights obligations. Torture and other ill-treatment are absolutely prohibited under international law and there is no justification for it. This appears to be nothing more than tit for tat policing operations targeting people based on their ethnicity and nationality.

Struthers called for both nations to independently and impartially investigate the recent detentions. The situation raises significant concerns about due process and the rule of law.

A recent wave of detentions involving Russian and Azerbaijani nationals is the most recent controversy surrounding human rights in the two bordering nations. On June 27, Russian authorities detained around 50 ethnic Azeris in Yekaterinburg for alleged past crimes. Detainees reported torture, and two individuals died while in custody, although Russia attributes the deaths to heart failure.

In a move of possible retaliation, Azerbaijan authorities detained at least eight Russian nationals in Baku, the country’s capital, between June 30 and July 1. The detainees, held on charges including espionage and drug trafficking, have reported abuse while in custody.

Azerbaijan and Russia have significant ties due to shared borders, intertwined economies and energy exports, and ethnic diasporas. Tensions have been on the rise between the two nations in recent years, heightened by political fallout from the Russo-Ukrainian War. This past December, an Azerbaijani plane crashed while in Russian airspace, with strong indications that the plane was shot down by Russian missile defense systems.

The recent detentions signal a developing diplomatic crisis between the two countries, with each side accusing the other of targeting people based on ethnicity and nationality.