Nairobi/Djibouti  - United Nations-brokered peace talks aimed at ending an increasingly brutal conflict in Somalia have broken down with the UN's special envoy calling an end to the latest round of meetings.

"I made the decision to terminate the conference," the BBC reported UN envoy for Somalia Ahmedou Ould-Abdallah as saying at a news conference in neighbouring Djibouti late on Sunday.

Government and opposition officials have refused to meet face-to- face in Djibouti, with the presence of Ethiopian troops in Somalia a key bone of contention.

The Islamic opposition says that the Ethiopian troops must leave before progress can be made in peace talks, but the government is concerned that pulling out the troops will leave a security vacuum.

African Union peacekeepers from Uganda and Burundi are present in Somalia, but they number only a few thousand - around a quarter of the force supposed to be on the ground.

Somalia has been in a state of anarchy since the overthrow of dictator Mohamed Siad Barre in 1991, but aid agencies are now warning that the conflict is worsening and that the Horn of Africa nation is facing a massive humanitarian crisis.

Violence has ramped up in Somalia since transitional federal government troops and their Ethiopian allies in late 2006 wrested control of Mogadishu from the Union of Islamic Courts (UIC).

Al-Shabaab, the armed wing of the courts, has since waged a bloody guerrilla war that shows no sign of letting up. The group said it would step up attacks after an US airstrike killed its leader Aden Hashi Ayro in early May.

Dozens were killed over the weekend alone in heavy fighting in Mogadishu. (dpa)