Fixed penalty notices for nuisance behaviour will be extended to under-16s "as soon as possible", Tony Blair said.
Anti-social behaviour brings misery to many residents
A number of on-the-spot fines for offences such as throwing fireworks and
making hoax 999 calls were applied to 16 and 17-year-olds on Tuesday.
The PM told MPs: "A lot of anti-social behaviour, I am sorry to say, is caused by youngsters under the age of 16.
"It is precisely for that reason that we have the power to extend fixed penalty notices to them.
"We are looking at the moment as to the timescale in which we can do it but I very much hope we can do it as soon as possible," he said.
The issue was raised by Labour's Siobhain McDonagh who said a "large amount" of anti-social behaviour was perpetrated by younger teenagers.
She said the new fines should be extended if they prove to be effective.