FBI does not believe suspect was solely responsible, assistant special agent says, after attack that killed 15

• New Orleans truck attack – latest updates

Investigators were on Thursday intent on finding out who else may be behind the truck attack in New Orleans early on New Year’s Day that killed 15 and injured dozens when the chief suspect, 42-year-old US citizen, Shamsud-Din Jabbar, drove a pickup truck into a crowd on busy Bourbon Street.

Jabbar was killed in the attack as he shot at police and was shot to death as law enforcement returned fire.