The pair, both aged 17, were injured in the shocking incident on Sunday afternoon, which happened when the shopping centre was packed with families.
Horrified onlookers were evacuated from the area and videos circulating on social media show trails of blood through the mall as well as a huge knife discarded outside a branch of Boots.
Detectives have reassured the shocked public that they have increased police patrols in the area as they continue to appeal for witnesses to come forward.
“This happened in broad daylight in a busy shopping centre and has obviously caused some real concern to members of the public, Bedfordshire’s Detective Inspector Jackie Dadd said.
“Such violence in a public place will not be tolerated and we are committed to tackling anyone who thinks it is acceptable to act in this manner.
“We are aware that there are a lot of images and video being circulated on social media, and would urge anyone who captured the incident on their phones to contact police.
“We are also keen to speak to anyone who has any information about what happened.
(2/2) The Mall is currently closed while an investigation is ongoing. Anyone with any information, or anyone who was in the area at around 2.30pm and witnessed anything, is asked to call 101 quoting reference number 184 of 21 January. pic.twitter.com/OM0bKFmX9G— Bedfordshire Police (@bedspolice) January 21, 2018
Update: Following the incident at The Mall in Luton yesterday (21/01/18), we can confirm The Mall has re-opened. If you have any info about the incident you can tell us about it online https://t.co/167TSQJvHm— Bedfordshire Police (@bedspolice) January 22, 2018
“We will be increasing patrols in and around the Mall and Luton town centre and would encourage anyone with any information about Sunday’s incident to contact police on 101.”
Police were called to The Mall, near University of Bedfordshire, at around 2.30pm on Sunday.
Video footage also shows shoppers walking among bloody footsteps while paramedics appear to treat the victims behind a screen.
The mall was later closed and cordoned off while an investigation was carried out. It reopened on Monday morning.
Anyone with any information should call DI Dadd on 101 or Crimestoppers, anonymously, on 0800 555111.