MANILA, Sept. 12 (Xinhua) — Philippine Abu Sayyaf terror group has become stronger following the 9/11 terror attacks in the United States, a senior government official has said.

Presidential Communications Office Secretary Martin Andanar said on Sunday that the September 9, 2001 terrorist attacks in the U.S. opened a "Pandora's box" in terrorism.

"There comes the extremists, the ISI(Islamic State). The Abu Sayyaf group has become stronger," he said, citing the reported allegiance of the local terrorist group to the IS.

During the height of the al-Qaida, which was responsible in the U.S. attacks 15 years ago, the Abu Sayyaf bandits also pledged allegiance with the terror group.

Andanar said the 9/11 attacks should be a reminder that "all of us are facing a faceless enemy, terrorists."

He asked everyone to cooperate in the fight against terrorism.

"We should all be one in battling this, we should all be helping each other. This is not only the responsibility of the authorities, of the Philippine National Police and the AFP (Armed Forces of the Philippines). This is a responsibility of every Filipino," Andanar stressed.

Suspected Abu Sayyaf bandits recently attacked southern Philippine city of Davao, killing 14 people and injuring 70 others.