Staff members at the Amnesty International base in Moscow were unable to enter their office on Wednesday after officials sealed it overnight.

Sergey Nikitin, the head of Amnesty International in Russia, said when employees "arrived at our office this morning, they found that the door was broken and there were new locks."

Photos on Wednesday showed the door sealed with an official notice from Moscow city authorities and the old locks on the ground.

On Twitter, the organization wrote they "were not amused" by the situation and that they are working to resolve the issue soon.

Staff member Alexander Artemyev told Reuters news agency that officials cut off power to the office and that no prior warning was given.

The human rights group has been renting the office from the Moscow city government for over 20 years. The Moscow state property department had no immediate comment on the situation.

Rights organizations that receive foreign funding and are critical of the Kremlin have come under increasing pressure from authorities over the past few years.

The groups complained about staff intimidation as well as controversial laws regulating the operation of non-governmental organizations.

Russian authorities have designated some of the groups as "foreign agents," which subjects them to heightened scrutiny from officials.

Amnesty International regularly criticizes Russian authorities for their harsh treatment of prisoners and urges the release of people who have been jailed for political reasons.

On Tuesday, the group urged authorities to "end the pattern of impunity for torture and other ill treatment" after Russian activist and anti-Kremlin protester Ildar Dadin said he had been beaten and threatened in jail.

rs/sms (AP, AFP, Reuters)