"Our leaders owned this war on terror for the sake of dollars," Khan told the crowd assembled around the country's most important national monument, the Minar-e-Pakistan in Lahore.
"Let me curse you. You sold out the blood of innocent people," The Telegraph quoted him, as saying.
Amid speculations that an estimated 1,00,000 people had gathered at the rally, Pakistani political analyst Mosharraf Zaidi said that the rally was significant because Khan's party, Pakistan Tehreek-e-Insaf, had never managed to attract such large crowds in the past.
The support of the crowd also indicated that his message had managed to influence many gathered there, with some saying that they were fed up with the country's chronic insecurity and economic failure.
"I have come here to register my hatred against this corrupt system," said a 29-year-old man, who attended the rally, said.
A poll conducted by the US-based Pew Research Center in June found Khan, the captain of Pakistan's 1992 world champion cricket team, to be the most popular political figure in the country.
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