Prime Minister Ariel Sharon, the most powerful Israeli leader in 50 years, has died, Middle East Newsline reported. He was 77. Sharon was declared dead by physicians at Jerusalem's Hadassah Hospital before 1 p.m. Israeli time [6 a.m. EST]. Authorities have already been notified of the death, and a government announcement was expected to be issued over the next hour.However wire reports said Sharon underwent emergency surgery to stem fresh bleeding in his brain. Reuters reported that after the nearly five-hour procedure, Sharon was taken for a computerized scan of his brain to determine its success. A spokesman for Jerusalem's Hadassah hospital said an update on his condition would be released after the scan, according to the Reuters report. The prime minister was felled by a massive stroke on late Jan. 4. A nine-hour operation failed to repair what physicians and officials termed was widespread damage to his brain and other vital organs.