Officials on the southern Philippine island of Basilan say thousands of people are fleeing as government troops prepare to battle Muslim rebels.
Philippine defense officials say they are poised and ready in Basilan, but stress that they are only going after individuals they say are responsible for the deaths of 14 marines earlier this month.
The army had originally given the Moro Islamic Liberation Front (MILF) until Sunday to surrender members responsible for killing the Philippine army marines. The marines were killed earlier this month. Ten of them were beheaded.
MILF refused to meet the deadline.
The rebels admit to killing them, but deny the beheadings. The rebels have called for an investigation.
The tense stand-off between the two sides threatens to derail ongoing peace talks.
The rebels have been fighting for self-rule in the southern region of Mindanao - where Basilan is located - for nearly three decades. In 2003, the government signed a truce agreement with MILF, but clashes continue.
Some information for this report was provided by AFP.