An adviser to Iraq's prime minister said Thursday that radical Shiite cleric Muqtada al-Sadr is in Iran, but denied he fled due to fear of arrest during an escalating security crackdown. Sami al-Askari said al-Sadr traveled to Iran by land "a few days ago," but gave no further details on how long he would stay. A member of al-Sadr's bloc in parliament, who spoke on condition of anonymity because of fear of reprisals, said he left three weeks ago. "I confirm that Muqtada al-Sadr is in Iran on a visit," said al-Askari. "But I deny that his visit is a flight."Another lawmaker loyal to al-Sadr, Saleh al-Ukaili, insisted that al-Sadr is in Iraq and claimed the accounts of his departure were part of a "campaign by the U.S. military" to track down the elusive cleric. U.S. and Iraqi forces have increased pressure on backers of the anti-American cleric and other militants in a major security operation that began in force this week. Conflicting reports on al-Sadr's whereabouts have been exchanged for days.