Fighting has resumed in the Somali capital, Mogadishu, following UN warnings of a humanitarian disaster.

"My house was crashed, collapsed by the mortars of the Ethiopian troops," resident Issa Gedi told the BBC.

"One of my sons died," he said by telephone, as shots could be heard in clashes between Ethiopia-backed government troops and insurgents.

Only fighters and men protecting their property are in the city as women and children have fled, aid workers say.

More than 200,000 people have fled their homes since Ethiopia troops helped the government oust an Islamist group from Mogadishu in December, the UN says.

Most people lacked food and water and hundreds had already died from cholera and diarrhoea, UN humanitarian co-ordinator Eric Laroche said.

"It is time that we get access to the people in Mogadishu," he said.

BBC East Africa correspondent Adam Mynott says the displaced are living scattered across southern and central Somalia in appalling conditions.

There are also claims that the transitional government has blocked aid from getting to some of those who need it.

'Improving'

The latest clashes have been in south Mogadishu, seen as an insurgent stronghold.

At least 20 people were killed on Thursday, with heavy artillery being used in residential areas.

"The rest of my family fled because they could not [bear to] see the flesh of my son, who is lying in the middle of the house," Mr Gedi told the BBC World Today program.

However, President Abdullahi Yusuf told the BBC that the situation was slowly improving, blaming the latest violence on the Islamists.

"Our aim is to protect the public and the government from attacks of these remnants of the Union of Islamic Courts [UIC] because they are assassinating everyone to reckon with in Somalia who they think would sympathize with the government," he told the BBC.

He also said the unpopular Ethiopians would have withdrawn by now if the violence had not continued.

The renewed fighting in Mogadishu comes after at least 20 people were killed on Thursday after an Ethiopian convoy was mined 20km from Mogadishu on the southern road to Afgooye.

Eyewitnesses said there had also been a big explosion at an Ethiopian army complex south of the city.

Correspondents say it is not known what triggered the fighting in the city on Thursday morning.

"Six consecutive missiles hit... There are many wounded," said Hassan Ibrahim, as he drove a minibus full of the wounded to a hospital.

The shelling was centered around the central presidential palace, the former defense ministry and a former secondary school in the north.

An eyewitness who saw the explosion at the Ethiopian army base told the BBC Somali service the rising debris and smoke looked like a "flying mountain".

He said people fleeing the area told him that after the blast Ethiopian troops started firing at people passing by; bodies are reported to be strewn along the street.

Intensified

The insurgents are believed to be a mixture of Islamist fighters and militiamen from the Hawiye clan - the largest in Mogadishu.

Violence has intensified this year after the relative calm when the UIC ran the city.

Somalia has not had an effective national government for 16 years.

Last month, more than 1,000 people were killed in the heaviest fighting sine 1991.

The Ethiopian troops have started to withdraw, to be replaced by an African Union peacekeeping force.

But only 1,200 troops, of the 8,000 the AU says it needs, have been deployed.

Photo caption

Ethiopian troops in Somalia