Officials with the FBI provide an update Sunday on their investigation into last Wednesday's deadly truck attack on Bourbon Street in New Orleans.

A man in a rented pickup truck rammed into a crowd of people celebrating New Year's Day in the city's French Quarter, killing 14 people and injuring dozens of others in what is being investigated as an act of terrorism. 

The day after the rampage, the FBI said the driver of the truck acted alone, countering initial suspicions that he may have had accomplices.

Investigators say they are continuing to look into what motivated Shamsud-Din Jabbar to carry out the attack before he was killed by police during a firefight. The former U.S. Army soldier proclaimed his support for the Islamic State militant group in online videos posted hours before he struck.

WATCH | Attack was 'premeditated and an evil act,' FBI official says:

New Orleans attack was 'premeditated and an evil act,' FBI official says

FBI official Christopher Raia said Thursday that investigators do not believe at this point that anyone other than the accused was involved in the New Orleans truck attack, which he described as an 'act of terrorism' that saw 14 innocent people killed.

Victims were remembered at a vigil in the city on Saturday night, and U.S. President Joe Biden plans to visit New Orleans on Monday to grieve with victims' families.