The United Nations food agency has suspended aid work in the southern Philippines after a spate of deadly bombings in the region.

The U.N. World Food Program feeds more than 300,000 families displaced by conflict in the southern Philippines. On Wednesday, the Manila office advised its staff in the region to suspend food distribution this week because of a series of deadly bombings.

Alghassim Wurie, deputy director of the WFP in the Philippines, says the agency acted in response to a United Nations advisory on travel to parts of Mindanao island.

"Currently, our colleagues are networking with the authorities to understand how things are happening in Mindanao," said Wurie.  "If it has calmed down by the end of the week, we will hopefully resume work early next week."

Investigators look for evidence after a bomb blast at a commercial center in Jolo, on the island of Mindanao, 07 Jul 2009

At least six people were killed and scores wounded in a series of blasts Tuesday in Jolo and Iligan city. The WFP has an office in Iligan as well as in Cotabato, where an explosion killed five people Sunday.

Militants in the south have in the past kidnapped aid workers. The extremist Abu Sayyaf group is holding an Italian Red Cross worker.

Security authorities are still investigating the recent bombings. No one has claimed responsibility for the attacks.

Philippine Executive Secretary Eduardo Ermita said Wednesday authorities are looking into the separatist Moro Islamic Liberation Front's special operations group.

"From our experience, the signature showed that with the use of 60 and 81 millimeter mortar rounds as elements in the improvised explosive devices, this is the handy work of the special operations group which is supposed to have been trained by Jemaah Islamiyah trainees from the outside," said Ermita.

Jemaah Islamiyah is a regional terrorist network blamed for deadly bombings in Indonesia, including the Bali blasts in 2002 and 2005. Security officials say JI militants have sought refuge in Mindanao.

The MILF has denied any role in the attacks. Representatives of the government and the MILF are in Kuala Lumpur this week hoping to restart stalled peace talks to end more than three decades of separatist insurgency. The Philippines is predominately Christian, but there is a large Muslim population in the south.