General Santos City, Philippines  - Twenty-five people were wounded when a hand grenade exploded at a New Year's Eve party in a southern Philippine city, a regional police chief said Thursday.

Chief Superintendent Fidel Cimatu said the explosion occurred Wednesday in a plaza in General Santos City, 1,080 kilometres south of Manila, where hundreds were attending a New Year's Eve party.

Cimatu said one of the victims - a woman - was in a serious condition after suffering a head wound in the explosion.

Police were still identifying suspects in the attack. Investigators on Thursday had not yet determined a motive. (dpa)