Vahid Salemi, Associated Press
Mahmoud Ahmadinejad

TEHRAN, Iran — President Mahmoud Ahmadinejad tightened his grip on Iran's powerful intelligence services, ousting four senior officials in a widening purge against authorities who challenged the harsh crackdowns after June's disputed elections, lawmakers and media said Monday.

The shake-up at the Intelligence Ministry — the nation's main spy agency — deepened the rifts straining Iran's conservative ranks over Ahmadinejad's strong-arm political tactics and the crushing response to the pro-reform opposition since the June 12 election.

It also sought to bolster Ahmadinejad allies in the Revolutionary Guard, which led the assaults and arrests against protesters who claimed the election was rigged. But now officials from other groups, including the police and judiciary, say abuses occurred and have called for investigations into the deaths and alleged torture.

The latest purge was reportedly linked to the refusal of some top officials to back the government's claims that the wave of protests were part of a "velvet revolution" aimed at overthrowing the Islamic leadership. Some in the ministry also had reportedly opposed broadcasting confessions by detainees that the opposition says were obtained by abuse.

The increasingly public disagreements have shattered the perception of high-level unity in the face of the postelection crisis and suggest Ahmadinejad's political capital is shrinking as he moves to form his second-term government this week.

The Intelligence Ministry sweep came less than two weeks after Ahmadinejad angered conservatives by firing the intelligence minister, Gholam Hossein Mohseni Ejehi, in an apparent dispute that reportedly included the handling of the clampdown on the unrest.

It left Ahmadinejad as de facto head of the Intelligence Ministry until the new government is formed as early as next week.

Pro-reform Web sites reported that more than a dozen senior ministry officials were fired or forced to resign in the past few weeks, but the total number remained unclear.

Conservative and pro-reform media identified four deputy ministers who were removed. They include the head of counterespionage and a 25-year veteran, both of whom were "trusted" by Supreme Leader Ayatollah Ali Khamenei, according to one conservative Web site Khabaronline.

Khamenei, the most powerful figure in Iran, has repeatedly backed Ahmadinejad since the election. But they differed over Ahmadinejad's selection of a top deputy, Esfandiar Rahim Mashai, and the president angered his hard-line supporters by initially refusing to back away from the appointment. He ultimately did.

Ahmadinejad also faced strong backlash from conservatives after dismissing Ejehi, the intelligence minister. Hard-line clerics denounced the removal in sermons, and 210 lawmakers in the conservative-dominated 290-seat parliament thanked Ejehi for his service to the country in an implicit jab at Ahmadinejad.

Khamenei did not immediately react to the latest Intelligence Ministry dismissals, which were ordered by Ahmadinejad.