Somali rebels have fired mortars toward the presidential palace in the capital, Mogadishu, killing at least seven civilians.

Witnesses and a military spokesman on Wednesday said the attack happened late Tuesday.  They said the mortars, aimed at the presidential mansion, hit a civilian neighborhood nearby instead.

Some reports said several government soldiers were also killed in the attack, but that has not been confirmed.

Islamist insurgent groups trying to topple Somalia's government launched an offensive early this month.  Fighting since then has killed nearly 200 people in Mogadishu.

The U.N. refugee agency on Tuesday said a total of 67,000 Somalis have fled the capital since the attacks against government targets began on May 8.

Some information for this report was provided by AFP and AP.