Commanders also fear that Somali factions could attack the marines.
Ethiopia has supported and is alleged to have supported a number of different Somali factions at one time or another.
The Somali factions agreed tonight to disarm and form a transitional government for the country.
Concurrently, various Somali factions returned to the negotiating table in an attempt to end the civil war.
All Somali factions were urged to negotiate and establish a transitional government of national unity.
Concern was expressed at the build up of weapons by Somali factions in several areas of the country.
He had succeeded in winning the confidence of the numerous Somali factions, the officials said.
Without such help, he said, the private groups were intimidated by demands from Somali factions.
The Somali factions meeting here squabble over who their spokesman is and what he should say.
But the deployment has been blocked by difficult negotiations seeking the assent of Somali armed factions.