central Somalia - including two large regions worst affected by a famine.

Earlier this month, it said its forces were making a tactical retreat from the capital, Mogadishu.

Last year the group bombed the Ugandan capital, Kampala, killing 76 people.

'Pariah state'

"There are serious allegations that Eritrea is supporting al-Shabab in destabilising the Horn of Africa and so we will be hoping to hear responses to those issues," the permanent secretary at Uganda's foreign ministry, James Mugume, told the AFP news agency.

A UN monitoring report released last month accused Eritrea of funding and arming al-Shabab - an allegation it rejected as propaganda aimed at discrediting it in the region.

Earlier this month Eritrea applied to rejoin the regional bloc, the Inter-Governmental Authority on Development (Igad).

It pulled out of Igad in 2007 afterthe body - made up of Kenya, Uganda, Djibouti, Ethiopia, Sudan and Somalia - supported Ethiopia's military intervention to back the weak government in Somalia.

Eritrea analyst Michela Wrong told the BBC Mr Afewerki's trip was the latest sign that he wanted to end Eritrea's isolation.

"Eritreans pride themselves on their rugged independence from the world, but I think there is a realisation this has reached dangerous levels. They are now regarded as a pariah state," Ms Wrong told the BBC's Network Africa programme.

image copyright Reuters image caption Eritrea's President Isaias Afewerki is trying to rebuild ties with regional leaders

"I suspect this is Eritrea reaching out to neighbours to say: 'We don't want to be completely on our own.'"

Eritrea gained independence from Ethiopia in 1993, but the two countries soon