A United Nations plan to help Somalia's fledgling government rebuild has been put on hold because of security concerns, a senior U.N. official said.

Four U.N. employees were kidnapped in Mogadishu in March, and the agency has decided a peace-building mission to the Somali capital will be postponed until the safety of the war-ravaged city improves, said David Stephen, the U.N. representative for Somalia.

``The hostage-taking in March was a big problem to the peace process and was seen in many quarters as proof that Mogadishu was not safe,'' Stephen said. The Nairobi-based U.N. political office for Somalia had begun drawing up the peace-building plan in January. A draft was to have been delivered to by the end of April, but the kidnapping halted the process, Stephen told The Associated Press Monday.

The hostages were released unharmed by their captors, who oppose the government. However, the United Nations is no longer sending international staff to the capital, pockets of which are controlled by faction leaders.

The mission plan was likely to have involved financial and technical support for the government of President Abdiqasim Salad Hassan. Significantly, it would also have involved stationing international U.N. staff in Mogadishu for the first time since a failed U.N. peacekeeping mission pulled out in 1995.

International observers have said the government has not lived up to expectations after it was elected at a peace conference in neighboring Djibouti last August. ``There is certainly a feeling that there has not been too much progress, but on the other side, the international community ... largely took an attitude of wait and see,'' said Francesco Sciortino, Italy's special envoy to Somalia. ``We were perhaps expecting a bit too much progress from a new government in an extremely difficult situation without money and without infrastructure.''

Since factional leaders ousted President Mohamed Siad Barre in 1991, then turned on each other, the eastern African nation had not had a central authority controlling the entire country. Many clan-based faction leaders oppose the new government, and the administration has little influence outside the capital.

The government has set up its own security forces but has tried to avoid confronting the faction leaders for fear of creating more clan warfare, diplomats have said.