Bhutto was the first woman leader of a Muslim nation in modern history and was assassinated on Dec. 27, 2007.
Hundreds of people gathered at the Shaheed Benazir Bhutto mausoleum to commemorate her life and the anniversary of her death, Geo News reported.
Pakistani President Asif Ali Zardari called on people to join hands and work together in her memory, the Associated Press of Pakistan said.
"While we pay tribute to her courage and leadership we also vow to continue to fight for the values she upheld and laid down her life for," Zardari said.
Sindh Home Minister Zulfigar Mirza said he knows who was behind Bhutto's assassination. He told Dawn News Bhutto's son, Bilawal Bhutto, was made aware of the information and details of the case will soon be made public.