Beijing has unleashed an \"uncompromising\" assault on China\'s legal profession, targeting human rights lawyers in an effort to head off social unrest, Amnesty International said Thursday. The move was a bid to control rights lawyers who take on sensitive cases as fears mount that uprisings in the Middle East and North Africa could take root in the world\'s most populous nation, the rights group said in a new report. \"Human rights lawyers are subject to escalating silencing tactics -- from suspension or revoking of licences, to harassment, enforced disappearance or even torture,\" said Catherine Baber, Amnesty\'s Asia Pacific deputy director. \"As part of the crackdown (on dissent), the government is rounding up lawyers associated with issues such as freedom of religion, freedom of expression and land rights,\" she added. Chinese authorities have launched their toughest campaign against critics of the government in years after anonymous online appeals emerged in February calling for weekly protests like those that have swept the Arab world. Rights lawyers and activists were among those rounded up, including Ai Weiwei, a prominent artist and government critic who was released last week after three months in detention accused of tax evasion. Authorities have ordered him to pay more than $1.9 million in back taxes and fines, a close friend of the artist\'s told AFP on Tuesday. Among the prominent lawyers rounded up at various points since February are Teng Biao, Jiang Tianyong, and Li Fangping -- vocal lawyers known for taking on sensitive cases often directed at government abuses. All have since been released but have maintained an uncharacteristically low profile since their detention. Teng was held for 10 weeks. Shanghai human rights lawyer Li Tiantian, who was released in late May from three months\' detention, wrote in a series of subsequent posts on Twitter that police presented her with intimate details of her sex life and threatened to ruin her reputation. The Amnesty report, \"Against the Law: Crackdown on China\'s Human Rights Lawyers\", said the country\'s rights lawyers have become a target because they \"use the law to protect citizens against the excesses of the state\". \"The Chinese state is attempting to wield and manipulate the law to crush those it perceives as a threat,\" Baber said. The report said authorities weed out undesirable lawyers through annual assessments, conducted by \"supposedly independent\" lawyer associations that often fail those who take on sensitive cases, resulting in their licences being suspended or revoked. Among China\'s 204,000 lawyers, only a \"brave few hundred\" risk taking on rights cases, while new regulations in recent years bar lawyers from defending certain clients or speaking to the media, Amnesty said. The changes have also made it easier to charge lawyers with crimes such as \"inciting subversion\" in the course of their work, it added. \"The measures have made legal representation more difficult to find for those who need it most,\" the report said, referring to groups including members of banned religious organisations such as Falungong, Tibetan activists and victims of forced evictions. \"Individuals who have suffered violations such as torture and illegal detention by the state are particularly vulnerable to inadequate legal representation,\" Amnesty added. \"Examples include individuals facing the death penalty, prosecuted largely on the basis of confessions extracted through torture.\" Prominent Chinese dissident Hu Jia was freed just days following Ai\'s release, after completing a more than three-year sentence for subversion. Hu, 37, was jailed in April 2008, just months before the Beijing Olympics, after angering the ruling Communist Party through years of campaigning for civil rights, the environment and AIDS patients.