Aid agencies say they are increasingly concerned about Iraqi civilians trapped in the besieged rebel city of Falluja.
The situation for Falluja residents has been described as desperate
Relief workers say no drinking water or electricity is available and food is short after days of street battles between US-led forces and insurgents.
Fighters are holding out against the US-led assault on the rebel stronghold for the sixth day of the offensive.
But US commanders say they now control 80% of the city and they expect major combat operations to be over soon.
BBC correspondent Paul Wood, embedded with US marines, says Friday night was the quietest since they arrived in the city.
Our correspondent says the marines, in the words of one senior officer, believe they have broken the back and the spirit of the insurgency in Falluja.
Insurgents have been hitting back with attacks and bombings elsewhere, with clashes in the capital, Baghdad, and the northern city of Mosul.
The Iraqi government is sending national guard reinforcements to Mosul after a second day of violence there.
The authorities in Baghdad have dismissed Mosul's police chief, after police stations were attacked and insurgents began roaming some streets at will.
A man who fled Falluja on Thursday told aid workers those left were in desperate need.
Up to 50,000 people may remain out of a pre-war population of 300,000.
The head of the Iraqi Red Crescent said a request to deliver supplies to civilians inside the city was turned down by the Iraqi government.
"There is no water, no food, no medicine, no electricity
and no fuel," Fardous al-Ubaidi told the Associated
"When asked for a permission, we were only
allowed to approach the Falluja outskirts," she added.
A Red Cross worker said movement was "impossible" in the city.
Wounded people bled to death before they could be helped, Ahmed al-Rawi said.
The agency has urged both sides to allow access for medical workers.
More than 7,000 families have taken refuge in three major camps set up on
the city's outskirts, the Red Cross told the Associated Press.
"The humanitarian situation in those displaced camps is
also deteriorating because of the lack of... very basic human needs," Mr al-Rawi said.
Our correspondent says a big civil affairs effort is planned for the city when the fighting ends.
Strategy against insurgents
US forces estimate they have killed about 600 insurgents since the assault began on Monday. They say 22 Americans and five Iraqis have been killed and almost 180 US soldiers wounded.
US commanders have said their strategy is to trap insurgents against the River Euphrates in the southern part of the Iraqi city.
Marines say they have already detained 150 insurgents, including more than 50 non-Iraqis, from Iran, Syria, Egypt, Saudi Arabia and Jordan.
The troops say they have cornered fighters loyal to Islamic militant Abu Musab al-Zarqawi in the south of Falluja.
But in a recording posted on an Islamist website, Zarqawi urged rebels to resist US forces, and assured insurgents that victory is only hours away.
US officials nearly doubled their tally of wounded on Friday, and bed capacity is reportedly being expanded at the main US military hospital in Europe - at Landstuhl in Germany - to cope with an influx of injured marines.
Some 10,000 US forces and 2,000 Iraqi troops are involved in the battle for Falluja.
The assault on Falluja, a hotbed of Sunni resistance, is officially aimed at helping to stabilise Iraq ahead of January's poll.