The criminal justice system is dealing with more offenders caught with knives or offensive weapons than at any time since the start of the decade, new figures show.

Last year, 13,081 offences of possession of an article with a blade or point resulted in a conviction or caution in England and Wales.

In addition there were 6,899 cases where the offender was found with an offensive weapon, and 1,002 where a knife or weapon was used to make threats against others.

The combined total of 20,982 offences is the highest number for a calendar year since 2010, when there were 21,328.

Last year’s tally was up by 9% on 2016, with the Ministry of Justice saying the increase in part reflects a 30% rise in police-recorded knife and offensive weapon possession offences in the year to September.

The data also show offenders were aged under 18 in 4,490 cases – a fifth of the total number handled.

Conviction of a knife or offensive weapon offence is now more likely to result in some form of custodial sentence, according to the MoJ report.

The average custodial sentence length has risen by 2.2 months in the last decade to 7.5 months in 2017.

More than four fifths (86%) of adult repeat offenders received a custodial sentence of some form last year, the statistics also showed.

The findings come amid concern about a surge in knife violence, particularly in London where there have been a number of fatal stabbings.

Justice minister Rory Stewart said knife crime is a “terrible threat”.

He added: “I am delighted we are prosecuting more people and sending them to jail.

“Be in no doubt, if you are caught carrying a knife, you will face a jail sentence.”