Mogadishu  - Islamic insurgents Tuesday attacked the presidential palace and airport in the town of Baidoa, the seat of the Somali parliament, killing at least one soldier and wounding six others.

Witnesses told Deutsche Presse-Agentur dpa that shells landed on and around the palace in the early hours of the morning.

The attack is the first time that Baidoa has been attacked since 2006, when government troops backed by Ethiopian forces chased the Islamists out of Southern and Central Somalia.

Sheikh Mukhtar Robow Abu-Mansor, spokesman for insurgent group Al- Shabaab, told reporters in Mogadishu that his organization was behind the attack.

"Baidoa is the last stronghold of the Ethiopians and this puppet government and I call on all our Mujahadeen to put pressure on Baidoa in order to eradicate them," he said.

Somalia's transitional government and some moderate opposition leaders signed a ceasefire in early June.

The peace deal specifies that Ethiopian troops should leave within 120 days of the ceasefire coming into effect provided sufficient United Nations' peacekeepers have been deployed to relieve an overwhelmed and undermanned African Union force.

However, the deal does not embrace all of the warring parties and significantly does not include Al-Shabaab.

"There is no any cease-fire agreement until the Ethiopians pull out of our country," Abu-Mansor said.

Abu-Mansor also said that Al-Shabaab was not responsible for the Sunday murder of the head of the United Nations' Development Programme and earlier murders of other prominent Somalis.

"Ethiopians and government soldiers are behind the important killings," he said.

Aid workers have been increasingly targeted for attacks and abduction Al-Shabaab leader Aden Hashi Ayro was killed on May 1 in a US airstrike.

Al-Shabaab said it would target foreign troops and workers to avenge Ayro's death.

The chief of the UN refugee agency UNHCR's Mogadishu programme was recently abducted and is still being held.

Al-Shabaab, the military wing of the Union of Islamic Courts (UIC), has been waging a guerrilla war against government troops since the UIC was ousted from power at the beginning of 2007.

The interim government has been unable to achieve stability in the Horn of Africa country, which has been plagued by chaos and civil war since dictator Mohamed Siad Barre was toppled in 1991. (dpa)