UPDATE (8:25 p.m.): President Trump's official statement on Tuesday's terror attack, followed by a message from Vice President Pence.
UPDATE (5:50 p.m.): The Halloween parade will go on as scheduled.
No terrorist organization has taken responsibility for today's attack at this time.
UPDATE (5:36 p.m.): ABC is reporting the suspect in custody is Sayfullo Saipov, a 29-year-old from Tampa. Saipov is alive and made statements in the hospital.
UPDATE (5:30 p.m.): President Trump has weighed in, and said the attack was committed by a "very sick and deranged person."
The driver has been identified only as a 29-year-old male, who was shot in the abdomen. No other identifying information has been released.
Here is a picture purportedly of the suspect:
UPDATE (5:24 p.m.): NYC Mayor Bill de Blasio has declared today's attack to be an act of terror. The death toll has now been raised from six to eight, with more injured.
The people were killed after they were run over by the truck, and the only person shot was the assailant. The firearms were "imitation" and were not real.
Gov. Andrew Cuomo said that there's no evidence that this attack was part of a larger plot or any additional threat to the city.
UPDATE (4:57 p.m.): The First Lady has tweeted her thoughts and prayers.
UPDATE (4:48 p.m.): The NYPD is now reporting that nine people were injured, not 15. The number killed remains at six, and more witnesses have confirmed that the attacker yelled "Allahu akbar."
UPDATE (4:35 p.m.): This story keeps getting a bit stranger. MSNBC has a video of the truck driver holding some sort of weapon, but it's unclear if this is a real gun or a fake gun. The weapon was also reported to be a BB gun.
The driver may have yelled Allahu akbar.
UPDATE (4:23 p.m.): Six people are reported killed.
UPDATE (3:44 p.m.):
The incident is not believed to be related to terrorism. (See later updates.)
An eyewitness report said it stemmed from a car accident:
A person is in custody after a shooting near Stuyvesant High School in Lower Manhattan, the NYPD is reporting. People are being advised to avoid the area due to police activity.
At least five people have been shot. According to one source, those injured were not police officers.
Others were reportedly run over by a box truck.
Mayor Bill de Blasio's office said there is "no active threat" to the area.