"We are forced to appeal because of the direct threat to the operation of human rights campaigners and organizations in Russia," says the rights activists’ appeal to Medvedev released Monday, the Interfax news agency reported.

The document, was signed by veterans of Russia’s human rights community: Moscow Helsinki Group hea Lyudmila Alekseyeva, head of the Civic Assistance committee Svetlana Gannushkina, and leader of the movement For Human Rights Lev Ponomarev.

They said that instances of attacks on civil activists in Russia had become more frequent, that their safety was not guaranteed.

"It is obvious that there are circles, which are extremely annoyed with human rights campaigners’ commitment to the principle of universality of humanitarian and democratic values, with their unwillingness to hush up flagrant and systematic violations by officials and authorities of the basic human and civil rights and freedoms," the document reads.

The rights campaigners also complained about more frequent searches of the offices of NGOs carried out by law-enforcement bodies.

They gave the examples of searches and seizure of office equipment at the Memorial society office in St Petersburg, which was seized by masked and armed agents bearing a search warrant, confiscating eleven hard drives from the group’s computers. The investigators also seized all the organization’s research and archive materials collated over the past 20 years.

A St. Petersburg court – in an unprecedented decision – found for Memorial in January, calling the reasons for the search and seizure of Memorial equipment “illegitimate.”

The Agora human rights organization in Kazan, and at the office of the Samara-based NGO Golos (Voice), have also been raided, and Bellona’s St. Petersburg offices last year were put through a so called “spot inspection,” severely hindering the work of the organisation as all employees had to focus their attention on financial accounting.

"We can see that today law-enforcement bodies can carry out searches and seizures, under any pretext, brazenly and with impunity, at any NGO, paralysing its work or even condemning it to the complete cessation of operations," the appeal by the human rights activists says.

"Unfortunately, over the last six months the practice of persecution of human rights activists has been gathering momentum," the authors of the document said.

Indeed harassment often reaches murder in the cases the human rights workers describe, making for a foreboding climate for activists and independent journalists alike.

Two weeks ago, Natalia Estemirova, 50, who collaborated closely with Memorial and Human Rights Watch to document human rights abuses in Russia’s war torn  Chechen Republic, was bundled in front of dozens of witnesses in Grozny to whom she screamed for help, into a car.

She was found dead later that day, shot several times, once in the head, in Nazran, the main city of the neighbouring republic of Ingushetia.

In a rare departure from the Kremlin’s stony silence on such matters, Medvedev immediately deplored the incident and said it would be investigated at the highest levels.

“She was doing a very useful job,” said Medvedev at the time. “She spoke the truth.”

Estemirova also worked closely with human rights lawyer Stanislav Markelov, 34, who was killed in January this year, along side Nataliya Baburova, 25, a reporter for the fiercely independent Novaya Gazeta. It was a brazen midday attack just blocks from the Kremlin.

At that time, Markelov had just finished a press conference protesting the early release of from prison of a Russian army colonel who had murdered an 18-year-old Chechen woman.

None of these crimes has been solved.

In April, Ponomaryov himself, one of the signatories of the written appeal sent to Medvedev, was beaten outside his home. Aside from leading the For Human Rights Movement, he is also a founding member of Memorial.

In February, 72-year-old opposition newspaper editor Yury Grachev was beaten in the Moscow suburb of Solnechonogorsk by unknown assailants. Police investigating the case dismissed the attack on the editor of the investigative newspaper that exposed numerous acts of official corruption as self-inflicted injuries.

In December, at least one unidentified assailant shot in the head and wounded Shafig Amrakhov, 51, editor of the Murmansk-based online regional news agency RIA. He died after a week in the hospital. Earlier the same month, two unidentified assailants attacked and beat Zhanna Akbasheva, a local correspondent for the independent news agency Regnum, in the North Caucasus Republic  of Karachai-Cherkessiya.

In November 2008 Mikhail Beketov, editor of the authority-rankling Khimskaya Pravda newspaper, was beaten nearly to death in the Moscow suburb of Khimki. His paper wrote exposés on corruption and campaigned on environmental issues.

Beketov’s supporters say he made enemies by campaigning against a plan to build a toll highway between Moscow and St Petersburg through a forest on the outskirts of Khimki.

These crimes, likewise, remain unsolved.