Teenage girl, 14, hit in arm after a shooting spree
The 14-year-old was shot in the arm as homes and cars were also fired at in the Malabar area.
Police have seized one of the powerful pistols – believed to have been given as a Christmas present – but are concerned another may also have been used.
Officers received at least three reports of plastic BBs being fired at homes and cars.
And the teenage girl, who has not been named, was left with a welt on her arm after being hit in Cornish Crescent at about 5.30pm on Boxing Day.
PC Shane Tangye confiscated the "brightly-coloured" pistol the next day and interviewed its teenage owner. The gun is so powerful it is being sent for tests to determine whether it can be classified as an illegal weapon, possibly resulting in serious criminal charges, in addition to the girl's assault.
But Sgt Chris Manuell warned that such a weapon could "easily" blind someone or potentially see the carrier shot by armed officers, as has happened elsewhere in the country.
Last month 18-year-old Rachel Davies died after being shot in the eye and in 2007 Danny Marsh, 17, of Newport, Wales, died after being accidentally shot in the chest. Both incidents involved air rifles, rather than pistols.
Sgt Manuell added: "It would appear some young people were given the guns for Christmas and we've had several complaints from residents saying BBs had been fired at their windows, cars and even a child, who was shot in the arm.
"We attended the area and seized a gun from one youth and our investigation is ongoing into the alleged assault.
"On preliminary examination, the gun would appear to be of greater power than would normally be expected.
"Our concerns are the obvious safety risk that the guns would certainly have the capability of blinding someone.
"But we also need to get the message across that these are not toys and for parents to buy them for their children is highly irresponsible.
"If a member of the public reported somebody carrying a gun the implications could easily include the use of an armed response team. It is also a waste of police resources."
The force was also investigating the suspicion a second gun may have been used in a public place.
Police want to hear from anyone who knows of another gun being used in public, or has been targeted, on 08452 777444, quoting crime reference GT/08/3042.
