A bomb exploded in a Somali displaced persons' camp Thursday, shortly after a group of international journalists were in the area.

Camp officials told VOA that two Somalis were killed and five others were wounded in the blast, set off by a homemade explosive device planted in an food distribution office.

The journalists had just visited a feeding site near the camp in Mogadishu, near the former U.S. embassy. The reporters were on a one-day United Nations-led trip to the Somali capital to observe humanitarian aid efforts.

Meanwhile, two Somali insurgents hurled hand grenades at the U.N. compound on Thursday in a separate attack in the restive capital.

In response to the worsening violence, the international aid group Doctors Without Borders says it is closing its two largest medical centers in Mogadishu. Two of its workers were killed in the capital last month.

The group said it is shutting down the 120-bed facilities in Mogadishu's Hodan district, where it has been treating malnutrition, measles and cholera.

The director of Doctors Without Borders, Christopher Stokes, said it is hard to stop those services in an area where the group is saving lives, but that the “brutal assassination” of its workers makes it impossible to continue.

Mogadishu is one of the world's most dangerous places for foreign workers.

Somalia has not had a stable government since 1991. The militant Islamist group al-Shabab is attempting to overthrow the U.N.-backed government and impose strict Sharia law over the country.