Earlier Alvarez Isnaji, the mayor of the Indanan area on Jolo who has been trying to secure the hostages' release, said the kidnappers had threatened to harm the hostages if the ransom was not paid.
The last telephone contact was early on Monday, he said.
The ultimatum came after military reinforcements despatched to Jolo at the weekend shelled a forested area, targeting the Abu Sayyaf fighters.
|Troops sent to the island have shelled Abu |
Sayyaf positions [GALLO/GETTY]
Drilon, an anchorwoman for ABS-CBN, her cameramen Jimmy Encarnacion and Angelo Valderama, along with Muslim academic Octavio Dinampo, were heading to a meeting on Jolo island when they were seized on June 8.
The team had been hoping to interview a senior Abu Sayyaf leader.
The abductors freed Valderama on June 12 after a ransom of $2,250 was paid.