Three days of fighting in the Somali capital Mogadishu displaced 88,000 people from their homes, adding to hundreds of thousands who fled violence earlier this year, the United Nations said on Thursday.

In an unprecedented statement, 39 aid agencies also said they could not respond effectively to Somalia's unfolding humanitarian catastrophe due to insecurity in the Horn of Africa nation that has been in turmoil and anarchy since 1991.

Almost 90,000 people have fled Mogadishu or moved to safer areas within the city to escape the latest outbreak of violence, the U.N. refugee agency UNHCR said of the fighting between Sunday and Monday.

That violence killed several dozen people, residents say.

You see groups of people spontaneously protesting, crying for help from the international community and wondering how long Mogadishu will keep on being destroyed, UNHCR quoted a staff member in Somalia as saying.

A U.N.-backed interim government set up in 2004 is struggling to impose real authority across the country.

Somali forces and their Ethiopian military backers face daily attacks from Islamist-led insurgents.

With foreign correspondents largely staying out of Somalia for security reasons, and the international agenda dominated by other hotspots including Sudan's Darfur, aid workers say the Somali crisis is not getting the attention it deserves.

When allied Ethiopian and Somali government troops launched two offensives against Islamist hideouts in Mogadishu earlier this year, hundreds of civilians died and 400,000 people fled the coastal city, according to U.N. and aid group figures.

Most of those have not returned to their homes.

Many live by the roadside or in flimsy shelters, short of food, water and basic healthcare.

TOO MUCH SUFFERING

The exodus this year from Mogadishu -- a city of between one and two million, depending on estimates -- has been the worst such refugee movement in Somalia since the war that brought down dictator Mohamed Siad Barre in 1991.

Everyone is afraid that the lull in fighting is not going to last. They fear the insurgents are organizing themselves and that violence is going to be unleashed on an even higher scale, UNHCR quoted a Somali aid worker as saying.

About 46,000 refugees have settled along the road between Mogadishu and Afgoye town, to the west, UNHCR said.

Entire families are now crammed in tiny huts, its staff member said. Those who arrived this weekend were hoping to go back to the capital in a matter of days, but now they see their relatives who have been here for months, they lose hope.

The United Nations' humanitarian coordinator for Somalia, Christian Balslev-Olesen, said 100 people were injured at the weekend, adding to 3,400 war-wounded civilians since January.

Far too many people have been caught in the crossfire, he said in Nairobi where most agencies dealing with Somalia have their headquarters.

There are now roughly 450,000 people who have been displaced by fighting this year, bringing the total number of displaced persons in Somalia to more than 800,000, he added.

These events are occurring in a dramatically deteriorating humanitarian context in which more than 1.5 million people are in need of humanitarian assistance and protection.

As well as insecurity, checkpoints and ad hoc taxation were also halting aid distribution, Balslev-Olesen said. The Somali people have suffered far too much and far too long.

Sudan Somalia