Taylor Swift Terror Plot Suspect Started Working at Venue Days Before Shows

8:30 AM — Austrian authorities have released a few more details … explaining the 15-year-old who was detained claims the 19-year-old asked him to secure an ignition device. Unclear if he did.

We also have further clarification on some of the chemicals found in the 19-year-old’s home … with cops saying they found a barrel of hydrogen peroxide — used in makeshift explosives. He allegedly downloaded bomb-making instructions … further evidence this was an amateur attempt.

Authorities say the whole of Europe’s on high alert … with concern ISIS is using Austria as an “operational area.”

7:59 AM PT — More details are emerging about the suspects’ alleged actions in the lead up to their arrests … with CNN reporting the 19-year-old suspect quit his job back in July and changed his appearance — telling people around him he had something big planned.

Cops allegedly found 21,000 euros of counterfeit cash and a blue police light for his car to get better access to the arena’s periphery. CNN says he planned to kill himself during the attack either during a standoff with police or an explosion.

CNN says the 17-year-old suspect broke up with his girlfriend recently — possibly a trigger that sent him down this path.

Interestingly, CNN reports the 15-year-old who was detained may have just known about the plot … and may not have played an active part in its planning.

Taylor Swift‘s foiled terror attack got a lot further down the road than many initially thought … with one suspect employed by the venue just days before the singer came to town.

A 17-year-old suspect behind the near disaster in Vienna got a job at Ernst Happel Stadium in the days leading up to her shows … seemingly to better position himself and his accomplice for their alleged terror attack. He was arrested outside the venue.

As we reported, authorities executed a search warrant at the home of one of the suspects and found chemical substances and technical devices, presumably to make a bomb. Although authorities didn’t say, it appears that device could have been detonated by the 17-year-old who would have been working inside the venue.

It gets even more terrifying … authorities now say this would have been a multi-pronged attack. One of the terrorists allegedly planned to drive a vehicle into the crowd outside the venue — Taylor typically has fans outside listening who can’t get in — and immediately thereafter a bomb would have been detonated.

Cops have also arrested a 19-year-old and detained a 15-year-old … claiming the three individuals planned the attack.

A photo of the purported 19-year-old suspect has been circulating in foreign media, showing him with machetes — and he reportedly planned to use knives and machetes during the attack.

General Director for Public Security Franz Ruf says the suspects showed “concrete preparatory actions” in the lead-up … and, it’s no surprise authorities are calling this a “serious terror plot.”

As we told you … authorities say they feel confident they’ve minimized the threat of the same attack — but, the shows were canceled anyway because of the “abstract” threat of attack.

Austrian officials claim their main suspect — the 19-year-old — has fully confessed to the attack plans … with Director of State Security and Intelligence Omar Haijawi-Pirchner claiming the suspect felt it morally “right to kill infidels.” Authorities say all 3 suspects were radicalized online in the last month.

Nearly 200k people were expected between the three shows, but Barracuda Music said they felt they needed to pull the plug immediately — offering full refunds to the legion of disappointed fans.

The Vienna Tourist Board posted a condolence to all the Swifties … little comfort to the thousands of fans who flooded into the city to see the global pop sensation.