MANILA, Philippines ? (UPDATE) President Gloria Macapagal-Arroyo on Tuesday put parts of the troubled southern Philippines under emergency rule following a massacre of at least 24 people there, her spokesman said.

Spokesman Cerge Remonde said the proclamation covered the province of Maguindanao, where the massacre occurred on Monday, and two other neighbouring areas that together had a combined population of 1.54 million people.

"There is an urgent need to prevent and suppress the occurrence of several other incidents of lawless violence," Arroyo said in the proclamation, according to Remonde.

"The Armed Forces of the Philippines and the Philippine National Police are hereby ordered to undertake such measures as allowed by the constitution and by law to prevent and suppress all incidents of lawless violence in the aforesaid areas."

The state of emergency authorizes the military to impose curfews, set up checkpoints and undertake searches of homes.

The crisis began on Monday when armed men allegedly linked to Andal Ampatuan, the political kingpin in the area, seized more than 40 followers of a rival politician and journalists.

The bullet-riddled bodies of at least 24 among the group were later found in the area, while police were continuing to dig up newly dug graves on Tuesday in search of the others still missing.

Relatives of the some of the victims said the Ampatuan clan organized the massacre to stop a rival politician from filing his nomination to run as governor in next year's national elections.

The group had been part of a convoy travelling to an election office in which the rival candidate was going to be nominated for governor.

Fourteen of the people confirmed killed were women. Some of those killed were also reporters who had been accompanying the convoy to report on the attempted nomination.

The military said it suspected the Ampatuans were behind the massacre, but emphasized an investigation was under way.