BAGHDAD (Reuters) - Four Iraqi soldiers were killed in street fighting with Islamic State militants in Tikrit overnight as they advanced slowly into the city, a Sunni jihadist bastion, in the wake of coalition air strikes, a security official said.
The troops entered Tikrit's southern Shishin and northern al-Qadisiya neighborhoods on Friday, after the U.S.-led international alliance carried out air strikes against Islamic State, the officer from the Salahuddin province operation command told Reuters on Saturday.
The campaign was slowed on Friday evening by clashes with Islamic State that killed of four and wounded 11 other soldiers, the security official said, speaking on condition of anonymity.
Most of the Iranian-backed Shi'ite paramilitaries, which Iraqis call the Popular Mobilization Committees, or Hashid Shaabi in Arabic, are openly hostile to the United States and have opposed coalition air strikes.
The groups continue to hold their positions around the city's borders but, with the exception of the Badr Organization, are boycotting the current Iraqi military foray in protest against the coalition's involvement.
The force of more than 20,000 fighters and military personnel, the majority of them from Iranian-backed Shi'ite militias, launched the offensive on March 2, but it stalled two weeks ago, with officials citing high casualties among the fighters and concerns about civilians trapped in the city.
Iraqi military commanders called for coalition air strikes to break the deadlock, but Shi'ite militia leaders said they did not need help, least of all from the United States, which some view as their enemy and even accuse of aiding Islamic State.
Iraqi officials, speaking in private, described the U.S. government as unhappy with a Shi'ite militia-led assault on one of the largest Sunni Muslim cities in Iraq.
Sunnis have accused the Shi'ite militia fighters of displacing civilians and carrying out extra-judicial killings in areas they have liberated from Islamic State, including in eastern Diyala province and the farmlands surrounding Baghdad.
The decision by Prime Minister Haider al-Abadi to request U.S.-led air strikes on Tikrit came even though many Iraqi politicians believed he could not risk going against the wishes of the paramilitary fighters on the ground.
U.S. military officials, mindful of the controversy around their joining a fight in which Iran has provided critical military support, have describe the ground offensive as involving Shi'ite fighters not aligned with Iran.
(Reporting By Saif Hameed and Ned Parker; Editing by Raissa Kasolowsky)