Russian officials on Thursday inspected the offices of the country's oldest active human rights organization, the latest target in a wave of inspections of non-governmental organizations that activists are calling state harassment.

Lyudmila Alexeyeva, the head of the Moscow Helsinki Group, speaks to a Reuters journalist during an interview in Moscow, Russia, Jun. 26, 2012.

Two officials - one from the Moscow prosecutor's office, the other from the Russian Justice Ministry - arrived at the offices of the the Moscow Helsinki Group, which was founded in 1976. According to the group's founder, veteran human rights campaigner Lyudmila Alekseyeva, the officials asked for the group's charter and internal reports.

Officials made similar visits this week to the Moscow offices of Human Rights Watch, Amnesty International, Transparency International and several Russian human rights groups. Last week officials inspected offices belonging to Memorial, another Russian human rights group founded before the fall of the Soviet Union.

At least 80 organizations across Russia have been the targets of inspections in recent weeks.

On Thursday, the Moscow prosecutor's office launched three misdemeanor criminal cases against veteran activist Lev Ponomaryov, for refusing to hand over documents demanded during an inspection of the offices of his group For Human Rights earlier this week.

The Russian Prosecutor General's Office said Thursday that the inspections are part of the office's work to determine whether NGOs are in compliance with Russia's laws against extremism and money laundering.

A law signed by President Vladimir Putin last July requires NGOs that receive overseas financial support and engage in "political activity" to register with the Justice Ministry as "foreign agents." Critics say the law is designed to intimidate Kremlin opponents.