BEIJING, March 12 -- Chinese authorities would intensify campaigns against social ills ranging from corruption and terrorism to environmental pollution and wrongful convictions, according to work reports of two judicial bodies delivered Thursday to the top legislature.

Targeting high-ranking "tigers" in China's anti-corruption drive, prosecutors investigated 28 officials at the provincial or ministerial level and higher for corruption last year, a sharp rise from eight in 2013, said Cao Jianming, procurator-general of the Supreme People's Procuratorate (SPP), in his report at the annual session of the National People's Congress.

The 28 officials included Zhou Yongkang, a former member of the Standing Committee of the Political Bureau of the Communist Party of China Central Committee, and Xu Caihou, former vice chairman of the Central Military Commission.

From 2008 to 2012, a total of 30 officials at the provincial or ministerial level and higher faced investigation for corruption or other job-related crimes, according to Cao's report delivered in 2013.

In campaigns to combat lower level "flies," prosecutors probed 3,664 cases of graft, bribery and embezzlement of public funds involving more than 1 million yuan (164,000 U.S. dollars) last year. A total of 4,040 public servants at county level and above, including 589 at and above city or bureau level, were investigated.

A total of 55,101 people were investigated for duty-related crimes in 41,487 cases, an annual increase of 7.4 percent in the number of people, according to the report.

The work report of the Supreme People's Court (SPC), delivered by chief justice Zhou Qiang, showed that Chinese courts in 2014 convicted and punished 44,000 criminals in 31,000 cases of embezzlement and bribery, including severe cases such as Liu Tienan, former deputy head of the National Development and Reform Commission, and Li Daqiu, a former senior political advisor in Guangxi Zhuang Autonomous Region.

"Corrupt criminals shall be severely punished according to the law no matter how high their positions are and how powerful they are," Zhou Qiang said.

The SPP had the resolution to fight every corruption and punish every corrupt official, focusing on duty-related crimes committed by leading officials in key positions, Cao said.

Judicial authorities would strengthen fight against and prevention of duty-related crimes and commercial bribery in fields including food and drug administration, environmental protection, work safety, land sales, exploitation of mining resources and reforms of state-owned enterprises, according to the reports.

In line with lawmakers' proposal of imposing harsher punishment for those giving bribes to staff of state organs to pursue illegitimate interests, judicial organs handled more cases of such crimes last year.

A total of 7,827 bribers were prosecuted for criminal offenses, up 37.9 percent from the previous year, according to the SPP report, while the SPC report showed 2,394 people were convicted for offering bribes last year, up 12.1 percent from the previous year.

Authorities also pledged "zero tolerance" to judicial corruption which had raised public complaints these years.

Procuratorates investigated and punished 404 staff within their own system last year while 2,108 court officials were punished for violating disciplines and laws, according to the two reports, which vowed to "eradicate black sheep" in the judicial organs.