The 69-year-old was taken to hospital on Tuesday when his blood platelet count dropped to dangerous levels Nawaz Sharif has previously suffered heart problems and has diabetes ISLAMABAD: Pakistani leader Imran Khan said Thursday he was offering "sincere prayers" for his political rival Nawaz Sharif, after the ex-premier"s deteriorating health saw him moved from prison to hospital this week. Sharif, who served as prime minister three times before he was ousted in 2017, has been serving time in a Lahore jail for corruption. But the 69-year-old was taken to hospital on Tuesday when his blood platelet count dropped to dangerous levels, local media have reported. "Political differences notwithstanding, my sincere prayers are with Nawaz Sharif for his health," Khan tweeted Thursday, adding that he had ordered the "best possible health care and medical treatment" for him. Sharif"s younger brother Shahbaz, who took over the leadership of his Pakistan Muslim League-Nawaz (PML-N) party after he was jailed, tweeted his concerns earlier this week. "I am gravely concerned and worried on his fast deteriorating health condition," the younger Sharif wrote Tuesday. Nawaz Sharif has previously suffered heart problems and has diabetes. "Several tests are being taken to diagnose the exact nature of the disease and we have serious doubts about his health," another party stalwart, Khawaja Asif, told reporters in Lahore this week. The Supreme Court disqualified Sharif from politics for life over graft allegations in 2017, and he later received a seven-year jail sentence. He denies all the corruption charges against him and claims he is being targeted by the country"s powerful security establishment. Corruption is widely entrenched in Pakistan, with politicians regularly accused of misusing or stealing public funds and whisking the money out of the country. Khan"s new government, which took power in 2018, has launched a high-profile and controversial anti-corruption drive.