Active self-defence shall be undertaken only in the face of imminent danger

Luis Jalandoni, rebel leader

The rebel's political arm, the National Democratic Front (NDF), on Sunday announced a one-month ceasefire starting on 15 December.

Its New People's Army has fought an armed campaign against the government for more than 30 years.

President Arroyo said she hoped the break in violence would help revive stalled peace talks.

Self-defence

The two sides began negotiations in Norway earlier this year, but talks broke down in June following the rebel assassination of two members of congress.

Luis Jalandoni, a Netherlands-based leader of the NDF said the ceasefire would improve the atmosphere for a planned resumption of peace talks in January.

In a statement he said the rebels were to be ordered into a "defensive mode".

"Active self-defence shall be undertaken only in the face of imminent danger," he said.

A Christmas ceasefire is an annual tradition in the long conflict.

But military spokesman Brigadier General Edilberto Adan said he was worried the rebels might use the break in fighting to recover from recent battle losses.

He said the rebels declared a ceasefire after intensifying attacks on government troops and burning several telecommunications towers.

"They did their offensive operations with the end view of calling for a cease-fire," he told reporters.