Unidentified gunmen have abducted two Canadians, one Norwegian and a local woman from a tourist resort in the southern Philippines, army and police officials said Tuesday.

The incident reportedly took place late Monday night when the armed men stormed the Holiday Oceanview Samal Resort on Samal Island, near Davao City, the largest city on Mindanao Island, about 600 miles southeast of Manila. Regional military spokesman Capt. Alberto Caber said that two Japanese tourists at the resort tried to intervene but failed to save the four, who were taken hostages, the Associated Press reported.

"Four people were taken but we do not know what group was behind the attack," Caber said, according to Reuters, adding that about 30 foreign tourists were at the resort at the time of the incident. "It appeared the foreigners were the targets, they were not taken at random.”

The Philippine authorities reportedly identified the Norwegian as Kjartan Sekkingstad, the resort's marina manager, and the Canadians as John Ridsel and Robert Hall. The Filipino woman was not identified, but police said she is the partner of one of the Canadians.

The gunmen escaped with the four hostages in a boat and fled toward the Mindanao mainland, Reuters reported, citing a source. Three navy ships have been sent to search and intercept the gunmen's boat, and forces on the ground have also been alerted in southeastern Mindanao, an army commander reportedly said.

Military sources reportedly said Tuesday that the gunmen spoke English and Tagalog, a language spoken widely in the Philippines.

Caber reportedly said that a naval blockade has been set up around Samal Island to stop the boat from reaching Basilan Island, which is located farther to the southwest where Abu Sayyaf militants have strongholds and have often kept hostages while negotiating ransoms. Abu Sayyaf militants have previously attacked parts of the Philippines and targeted foreign tourists on several occasions.

In 2001, the al Qaeda-linked group, which was established in the early 1990s in Basilan province, about 100 miles northeast of Sulu, tried to seize hostages from the Pearl Farm Beach Resort, 17 miles south of Holiday Oceanview Samal Resort, during a ransom-kidnapping spree.

The Abu Sayyaf was recently declared a terrorist group by a Philippine court and has been on the U.S. Department of State’s list of terror organizations.