Bedfordshire Police is appealing for witnesses after the incident at around 3pm on Tuesday (April 12) in Strangers Way.
Three of the men fled the scene via a nearby alleyway and a man and woman drove off in a black vehicle.
PC Maureen Ude, investigating, said: “We are appealing to anybody who was in the area at the time of the incident and may have heard or seen something suspicious, please report this to us immediately.
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“Alternatively, if you live in the area and have any personal CCTV footage, please can you check your footage and share anything with us as a matter of urgency.
“Any information you have could help us establish the circumstances surrounding this incident.”
If you have any information to support this investigation, please call 101 or use the force’s online reporting centre and quote reference number 198 of Tuesday (12 April).
You can also give information to Crimestoppers anonymously on 0800 555 111 or via the Crimestoppers website.