Fighting resumes around Najaf shrine
Militants vow to quit mosque after Shiite leaders take over
Muqtada al-Sadr's militia still controls the holy mosque in Najaf.
CNN's Kianne Sadeq finds defiance inside the Imam Ali Mosque.
Iraqi interim Prime Minister Ayad Allawi is under pressure.
NAJAF, Iraq (CNN) -- Fighting between U.S. forces and fighters loyal to radical cleric Muqtada al-Sadr continued into the early morning hours Sunday, with explosions heard near the Imam Ali Mosque.
A series of blasts left fires burning around the shrine, one of the most sacred sites in Shiite Islam, about 1:30 a.m. Sunday (5:30 p.m. Saturday ET), witnesses reported.
The cleric's representatives had said al-Sadr's militia would vacate the mosque soon after handing it over to Shiite leaders.
During the hot afternoon, no weapons were visible as several hundred men, along with several women and at least one child, slept or cleaned inside the mosque courtyard in preparation to turn over control to Grand Ayatollah Ali al-Sistani.
An envoy of al-Sadr told CNN that he was sent to hand over the keys to the mosque to al-Sistani's representatives in Najaf, but was told that they would not accept them until fighting around the shrine calmed down.
The al-Sadr envoy told CNN that the al-Sistani representative promised to call for more guidance from the grand ayatollah, who is in London, England, for medical treatment.
"Al-Sadr's office has offered the keys of the shrine to the office of [the Grand Ayatollah Ali] al-Sistani and they have accepted this," the cleric's aide, Sayid Hazim al-Araji, told CNN.
"We want them to have these keys because we believe they can manage the mosque and take good care of it and care for all of the valuable items."
Representatives for al-Sistani have confirmed that the influential Shiite cleric "instructed his office in Najaf" to make arrangements to have control of the mosque turned over to the Shiite religious authority.
Al-Sistani ordered his office "to take the keys" from al-Sadr's people "to the holy shrine in Najaf."
The al-Sistani representatives have also been told to lock the mosque doors after the fighters leave.
An al-Sadr aide denied there were any weapons inside the mosque, insisting they would never bring them inside because that would be against Islam.
U.S. military officials in Najaf confirmed on Saturday that their forces resumed fighting with al-Sadr's Mehdi Army militia after a temporary halt.
Delegation expected for Najaf talks
A high-level delegation from the Iraqi interim government is expected to arrive in Najaf to try to meet with al-Sadr in an effort to bring a peaceful end to the standoff, U.S. military officials said.
There was no immediate time frame on when such a meeting might occur. The government wants al-Sadr and his militia to leave the mosque, disband and join the mainstream political process.
There was no immediate word on al-Sadr's location.
Friday began with confusion about what was happening in Najaf.
The governor reported that members of al-Sadr's militia were leaving the mosque and that at least 50 had been arrested at checkpoints in the city.
Earlier, the Iraqi Interior Ministry said police seized the mosque and detained 500 rebel fighters -- a claim that was later discounted.
Other developmentsThree Polish soldiers were killed Saturday in separate incidents near the central city of Hilla. One soldier was killed when attackers ambushed a convoy using improvised explosive devices and small arms. Two soldiers were killed when their vehicle exploded. The cause of the blast was unclear, but Iraqi police said there was no evidence of a roadside bomb.Insurgents hit a U.S. military vehicle with a rocket-propelled grenade early Saturday in southern Baghdad, killing one U.S. soldier and wounding two others, according to U.S. military officials. The attack happened about 12:30 a.m. (4:30 p.m. Friday ET).A roadside bomb attack Saturday in the northern Iraqi city of Mosul killed an Iraqi national guardsman and wounded three others -- two other guardsmen and a civilian -- according to an Iraqi police official. The bomb ripped through the guardsmen's convoy around 12:15 p.m. (4:15 a.m. ET) in the western part of Mosul, Gen. Mohammed Khairi Barhawi told CNN. An Iraqi police chief was detained Saturday on suspicion of being involved in criminal activities, a military spokesman said in a statement. Anbar Police Chief Ja'adan Mohammed Alwan was detained by the coalition on suspicion of "accepting bribes, extortion, embezzling funds, as well as possible connections with kidnapping and murder," 1st Lt. Eric M. Knapp said. Alwan's detention was authorized by the Iraqi Ministry of the Interior, Knapp said.
CNN's Kianne Sadeq in the Imam Ali Mosque contributed to this report.