MANILA, PHILIPPINES (AFP) - The death toll from an attack on a group of journalists and politicians in the southern Philippines rose to 35 on Tuesday after 13 more bodies were found, police told AFP.

"All 13 bodies were pulled from one grave," National Police chief Jesus Verzosa told AFP by phone from the scene of the massacre in Maguindanao province.

Twenty-two bodies had previously been found in a remote farming area of Maguindanao following Monday's killings by gunmen allegedly linked to the area's political kingpin.

The group abducted associates of a rival politician and a large group of journalists who were covering them.

Verzosa, who flew to the south to supervise the investigation, said he feared the death toll could rise with several other members of the kidnapped party of more than 40 people still missing.

"We still have to check one other suspected mass grave," he added.

Journalists on the scene said a mechanical digger was emblazoned with the name of the Maguindanao provincial governor, Andal Ampatuan, whose bodyguards had been blamed by the military as being behind the massacre.