UNHCR is alarmed by a string of recent security incidents targeting the Dadaab refugee complex in northern Kenya. Dadaab is the world's largest refugee settlement and shelters more than 460,000 people.

An explosion on Monday at the Hagadera camp killed one person and seriously injured two police officers. Another improvised explosive device went off on Tuesday near the market at Ifo camp. Although there were no casualties a police vehicle was damaged.

In total there have been four such incidents at Dadaab since October when three aid workers were kidnapped. As a result three Kenyan police officers have been killed and four others wounded. There have also been threats against humanitarian agencies working in Dadaab. UNHCR condemns these attacks and calls for respect for peace and the civilian nature of refugee camps.

"We are deeply concerned for the well-being and safety of Somali refugees in Dadaab, most of whom are women, children and elderly," said António Guterres, the UN's High Commissioner for refugees. "For the sake of refugees and those who are there to help them, it is of paramount importance to preserve the peaceful and civilian character of the camps."

A deadly mix of conflict, persecution, drought, and famine has seen 295,000 people fleeing Somalia in 2011. More than half have found shelter at the Dadaab refugee camps in Kenya. Others fled to Ethiopia, Yemen and Djibouti.

In Dadaab, development of new sites, registration, deliveries of emergency assistance and services continued uninterrupted throughout the year. However, since October, growing insecurity has crippled the ability of aid agencies to deliver all but life-saving assistance – mainly food, water and health services. UNHCR and its partners are exploring options to allow full operations to resume.

The situation in Dadaab has in recent months been additionally complicated by an outbreak of cholera, believed to have started among new arrivals who acquired it in Somalia or en route to Dadaab. Although new cases are now on a downwards trend, we have nonetheless seen 897 cases since August resulting in three deaths. Worsening security, rains and flooding have also affected the trucking of water to parts of the camps.

Somalia remains one of the worst humanitarian crises in the world. More than 950,000 Somalis live as refugees in neighboring countries while another 1.46 million are internally displaced.