Among the captives are three Americans and 14 Filipinos. While it isn't clear who the kidnappers are, or what their demands might be, it is believed they are hiding on some islets in the vicinity of Palawan island.
Authorities say the kidnappers are probably members of a rebel group.
However, they won't confirm reports that the Muslim separatist group the Abu Sayyaf is responsible for the kidnapping. This is the second time in as many years that the Philippine government faces the possibility of a hostage standoff. Asia More news from our Asia edition Last year, Abu Sayyaf gunmen took more than 40 people hostage, including a number of international tourists from the Malaysian tourist resort of Sipadan. This time Philippine officials say they at least will not be paying any ransom for the hostages. The latest saga began after about two dozen armed men wearing ski masks arrived in a large outrigger canoe at the Dos Palmas resort in Palawan's Honda Bay.