Philippines blast 'extortion bid'

Nine people were killed and 20 injured in the shop explosion

An extortion attempt may have been behind an explosion on the southern Philippine island of Jolo which killed nine people, police have said.

The grocery shop targeted in the blast had been sent a letter demanding money and warning of a bombing, local police chief Ajiron Ajirim said.

No-one has claimed responsibility but police say the al Qaeda-linked militant group Abu Sayyaf may be involved.

The separatist group is suspected of criminal activities to fund its fight.

A man held for questioning after Monday's blast has been freed.

The explosive device was planted on the ground floor of a two-storey building in Jolo town.

Those killed were shoppers and employees working in the Sulu Consumers' Co-operative, Senior Superintendent Ajirim said.

"The co-operative received a letter warning them that they will be bombed," he said. "It turns out they were extorting money."

Ordnance experts are expected to come from Manila to help in the investigation, Mr Ajirim said.

The bomb was made from the fertiliser ammonium nitrate and was rigged to a remote control device, he told AFP news agency.

Police have set up road blocks around the town.

A US military spokesman said American troops who were on the island on a humanitarian mission helped treat the 20 people wounded in the blast.

Infamous group

Philippine and US soldiers took part in a joint counter-terrorism exercise last month in Jolo, where Abu Sayyaf insurgents have been blamed for a series of attacks.

As the exercise started, a bomb attack at a bar near a Philippine Army camp on the island left one civilian dead and 20 others seriously wounded.

Abu Sayyaf is the smallest and most violent Islamic separatist group in the Philippines.

It is infamous for kidnapping Westerners and Filipinos, beheading victims and receiving large ransom payments. It was blamed for the bombing of a passenger ferry in 2004 which killed more than 100 people.

US-backed military offensives have considerably weakened the group to a few hundred rebels who are mostly on the run, according to the Philippine government.