The truck was loaded with munitions, then driven up a hillside in northern Syria. Moments later, there was a massive blast followed by cries of "Allahu Akbar," or "God is great" in Arabic, and the rattling of gunfire.

What made this suicide bombing stand out was not that it happened as such attacks have become fairly commonplace in war-torn Syria but the identity of one of the men who carried out.

In an online video and social media, radical Islamists claiming responsibility for the blast touted one of the attackers as Abu Hurayra Al-Amriki, an American.

Late Thursday, two U.S. officials confirmed their boast.

The man was a U.S. citizen who grew up in Florida and went to school there. Investigators are interviewing family members.

U.S. State Department spokeswoman Jen Psaki said Friday evening the American is believed to be Moner Mohammad Abu-Salha.

Whichever name one uses Abu-Salha or Al-Amriki he was among a group of Americans whom intelligence agents have been trying to keep tabs on since they went to Syria some months ago to join extremists in the fight against the Syrian government.

Abu Farouk al Shamy, a spokesman for the rebel Suqour al-Sham battalion, said that the Sunday attack was executed in coordination with the al-Nusra Front, an al Qaeda-linked organization that the U.S. government has blacklisted as a foreign terror organization.

One video on YouTube, with the title "the American martyrdom from al-Nusra Front," identifies the suicide bomber as Abu Hurayra Al-Amriki. This video and several other social media posts feature a picture of a bearded man with that name, smiling and holding a cat.

Al-Amriki in Arabic means "the American." The name Abu Hurayra, which is popular among Sunni Muslims, offers little clue as to the man's identity. Abu Hurayra was a companion of the Islamic prophet Mohammed and the narrator of Hadith.

Syrian activists say the video is from Sunday and shows militants' preparations and ultimate attack on Syrian military checkpoints in Jabal Al-Arba'een, near the city of Ariha in Idlib province and believed to be along a key rebel supply route.