Beijing ( CNN ) -- Prominent human rights activist Hu Jia , who was released over the weekend after serving a 3 1/2-year sentence , is promising his parents he will be `` careful '' in the future . In a phone call to CNN affiliate iCable News in Hong Kong on Sunday , Hu said his parents had asked him to not clash with the system . `` Once I saw my family , I understood how much I owe them , especially my parents , my wife and my kid . I realize I 've done nothing for them . There is a Chinese saying that 'patriotism and filial piety do n't go hand in hand , ' '' he said in the phone call . `` They told me to be a good citizen and do n't clash with the system . This system is very brutal . It uses government 's power to violate people 's dignity . I can only tell my parents , I will be careful . '' Chinese authorities released Hu on Sunday , days after freeing renowned dissident artist Ai Weiwei . Hu , 37 , denounced China 's human rights record in a series of articles ahead of the 2008 Beijing Olympics and was later sentenced to 3.5 years in prison for `` inciting to subvert state power . '' He also has been active on AIDS issues in China . Ai , the conceptual artist turned government critic , was released Wednesday on bail after authorities detained him for nearly three months for tax evasion , the state-run Xinhua news agency reported . On Sunday , police guarded entrances to Hu 's apartment compound and patrolled surrounding streets . Zeng Jinyan , his wife , appeared unreachable via phone or the Internet . Zeng told CNN Friday that authorities started 24-hour surveillance on her several days before Hu 's expected return . In an interview last December , she predicted a virtual prisoner 's life for the couple in their housing complex , called Freedom City . `` Hu Jia told me that he wo n't change , and police told him they may put him under house arrest in that case , '' she said . `` I 'm prepared for it . '' `` As long as there 's no democracy or the rule of law in China , our situation wo n't change at all . '' Last year 's Nobel peace laureate Liu Xiaobo , also a rights activist , was convicted of the same crime as Hu . Liu is still serving an 11-year jail term . Activists say the Chinese government , worried about potential uprisings inspired by the Arab Spring , has been increasingly tightening its grip on freedom of expression , targeting not only political dissidents but also intellectuals and artists . In his phone call to iCable , Hu talked further about his parents and his responsibility toward them and others like them . `` My parents are very old . How many parents are like my parents ? Others , too , are also in pain but not getting as much attention and help from you all as I did , '' he said . `` These people are more isolated . I can only try my best to comfort my parents and comfort the others too . ''
Hu : Politics and filial love do n't go hand in hand . The government uses its power to destroy people 's dignity , he says . He was released only after serving a sentence for ` ` inciting to subvert state power ''