More than 600 people gathered outside a hotel disco before a crush in which three teenagers died, police said.
Almost half have been interviewed by detectives probing the Saint Patrick’s Day tragedy in Co Tyrone.
Schoolchildren Morgan Barnard, 17, Lauren Bullock, 17, and Connor Currie, 16, died after people were trodden under foot near the entrance to the Greenvale Hotel in Cookstown on March 17.
Police Service of Northern Ireland (PSNI) detective chief superintendent Raymond Murray said: “By yesterday evening, detectives involved in the investigation had identified 619 people who were in the queue or car park on the evening of March 17th.”
He said 267 of those have been fully interviewed using appropriately trained detectives.
He added: “We will be continuing to interview others over the next few days.
“We are very aware that this continues to be an extremely traumatic time for all of those who were at the Greenvale Hotel and witnessed the terrible events of that night.
“We have taken considerable steps to make it as easy as possible for them to provide their statements to police.”
Over 100 people attended a dedicated room at Burnavon Arts Centre in Cookstown and spoke to officers who are specially trained in interviewing young people.
Police are speaking to students at their schools.
Investigators have used a major incident public portal to allow people to upload mobile phone footage and images of the evening.
They have been downloading mobile phone footage from people at the scene using a cyber support vehicle in Cookstown.
Police Ombudsman Dr Michael Maguire is to examine how police responded when the first emergency call was made at around 9.30pm.
The head of Ireland’s Catholic church, Archbishop of Armagh Eamon Martin, said the deaths had created a “valley of tears” as back-to-back funerals were held for the three youngsters last week.
Detectives appealed for anyone else with information to come forward.