The United Nations refugee agency says an increasing number of Somalis are fleeing to Yemen, despite the risky journey across the Gulf of Aden and the instability in Yemen.

The agency says that since January, 20,000 new Somali refugees have traveled to Yemen to escape the worsening security and humanitarian situation in their country.

The U.N. reported Friday that many new arrivals were apparently unaware of the unrest in Yemen, where the government has clashed with activists calling for an end to President Ali Abdullah Saleh's 33-year rule.

The unrest in Yemen has prevented many of the new refugees from moving around to find work and reach aid centers. So, the agency said, many are now considering returning to Somalia.

The agency expressed concern that the refugees will be targeted by human traffickers and smugglers along Yemen's Red Sea coast.

The U.N. said more than 300,000 Somalis have fled their famine-hit country so far this year. The majority are escaping to refugee camps in neighboring Kenya and Ethiopia.

Fighting has escalated in southern Somalia in recent months, where pro-government forces are trying to drive out al-Shabab militants. The al-Qaida-linked group is battling to overthrow the government and impose strict Islamic law.

The region grew even more unstable this week, after Kenyan troops moved into southern Somali to pursue al-Shabab militants suspected of crossing into Kenya to kidnap foreigners.