Iraqi army Captain Mohammed Ahmed said on Thursday that 150 of those arrested on Wednesday were Arabs from Syria, Sudan, Yemen and Jordan.
The joint forces have reported heavy battles on the outskirts of the city and several deadly bombings that have mainly killed civilians.
Iraqi authorities reported most of the civilian population had fled the city, which is 420km north of Baghdad and about 60km from the Syria border.
"Our forces arrested 150 non-Iraqi Arabs yesterday in addition to 50 Iraqi terrorists with fake documents as they were trying to flee the city with the (civilian) families," Ahmed said.
"We ordered the families to evacuate the Sunni neighbourhood of Sarai, which is believed to be the main stronghold of the insurgents," Ahmed said.
Eight civilians were killed in the city on Wednesday by a suicide car bomber at an Iraqi checkpoint, he said.
A journalist from Tal Afar, Nasir Ali told Aljazeera that heavy aerial bombing and artillery shelling was being undertaken in the area. The attack had destroyed homes, killed and injured innocent citizens, mostly children, women and the elderly, he said.
There was no exchange of fire as one would have expected fighters to engage in, Nasir Ali said.
Turkmen-dominated Tal Afar has
a thorn in the government's side
On Thursday, the US military said the combined American-Iraqi force had killed seven fighters over the past two days.
Tal Afar is 90% Turkmen and about 70% of them are Sunnis.
Early on Thursday, a website carried a videotape showing the destruction of a US Bradley Fighting Vehicle in Tal Afar. A US military official said two Bradleys had been hit by roadside bombs in recent days and a soldier was killed.
Also on Thursday, a bomber detonated his explosives-laden black BMW in the centre of Baghdad, targeting a passing convoy of private American security agents - the second attack in a week near the heavily fortified Sadir Hotel.
Three passers-by were injured, but there were no casualties in the three-vehicle convoy heading for the hotel, said police Major Mohammed Yunis.
The blast sent a huge plume of smoke into the sky over Rasafi Street in Baghdad's busy Karradah neighbourhood, a main shopping and commercial district.
The Sadir Hotel is used by foreign security agents and other Westerners involved in reconstruction in Iraq.
Meanwhile, a UN official has said Iraqi politicians have not finalised the country's draft charter, adding the world body would now wait for an amended text to be approved in parliament before printing the document.
"We don't think (the text) will be available until Sunday, they have to finish negotiations," Nicholas Haysom, UN official in charge of constitution affairs, said on Thursday.
"It leaves us very challenged, we don't mind what is in the final text"
Haysom said the text which had previously been authorised on 28 August was "subject to further changes", and that Shia, Kurdish and Sunni negotiators would now return to their respective leaders for approval before again seeking final ratification in parliament.the failure to deliver a final copy of the draft charter to the UN, with some negotiators suggesting different parties were seeking to present different texts.
The next session of Iraq's legislative body is not due until Sunday, said Haysom, who had previously warned the delays were disrupting the UN's task of distributing copies of the document before a scheduled 15 October referendum.
"It leaves us very challenged, we don't mind what is in the final text", as long as it has official approval by parliament, Haysom said.
Confusion reigned in Baghdad about the circumstances surrounding
The Iraqi legislative body's next
session is not due until Sunday
"This morning we were waiting for UN representatives to come and get the document, but they never came," said Bahaa al-Araji, a Shia member of the parliamentary committee charged with drafting the charter.
"The UN has no right to receive the text from the president's office," Araji added, suggesting that President Talabani's office had planned to hand over an amended text without parliamentary approval.
In renewed talks over recent days, politicians had debated whether to insert wording to clarify Iraq's "Arab identity" after complaints from Sunni Arab representatives and the Arab League that wording in the charter did not go far enough.
Talabani said recently that the draft constitution had been amended to satisfy those concerns.