Offenders who assault police officers may face jail terms of up to seven years and caning in serious cases, as the High Court unveiled a new sentencing framework that seeks to stiffen penalties in the wake of a spate of cop abuse cases.

There have been 688 cases of physical hurt against police officers in three years, and the court said the new framework is meant to reflect public outrage against such abuse as well as protect police officers.

The court issued a three-category framework in decision grounds on Wednesday, explaining why it increased by 10 times the one-week jail term of a drunk who slapped a police officer in April last year.

Noting that police officers were often the target in cases prosecuted under the relevant Section 332 of the Penal Code, the framework provides for punishments that range from a fine to up to seven years' jail.

The move towards stiffer terms comes at a time when sentencing trends show offenders can generally expect a jail term of three months where there are no aggravating factors, and higher terms of six to 12 months' jail for aggravated offences.

The court warned that "attacks against police officers can have several undesirable consequences at a societal level".

"All these issues are compounded by the increasingly complex and uncertain security environment with which modern-day policing is presented in a densely populated country, where emergency situations could arise at any time with dire consequences to the public," said Judge of Appeal Tay Yong Kwang, writing on the court's behalf.

Under the guidelines, where the offence involves lesser harm and lower culpability, the sentence will range from a fine to up to a year's jail, depending on the circumstances of the case.

Where the offence falls into the second category - which involves either greater harm and lower culpability or vice versa - then the punishment will range from between one year and three years in jail.

But where there is both greater harm and higher culpability, the sentence will range between three and seven years' jail, which falls into the third category.

The court also made clear that caning would generally be justified for offences that fall within the third category, such as cases where "inordinate violence" is shown, and even in some cases in the second category.

The harm would refer to the extent of the hurt to a particular police officer and the consequences to the police in general, while the "degree of culpability would be measured chiefly in relation to the manner and motivation of the offender's involvement in the criminal act", said Judge of Appeal Tay.

The court, comprising Chief Justice Sundaresh Menon, Judge of Appeal Tay and Justice See Kee Oon, said the proposed sentencing framework "seeks only to clarify and rationalise the existing state of the law and not to alter it. The sentencing framework also seeks to utilise the full range of sentences prescribed by law".

Wednesday's case concerned Jeffrey Yeo, 26, who had been jailed in Aprilby a district court after pleading guilty to slapping and hurling vulgarities at a police sergeant last year. The prosecution team, led by Deputy Attorney-General Hri Kumar Nair, sought to raise the one-week jail term on appeal, but Yeo's lawyer Henry Lim Ghim Siew argued thatthe sentence had to be "calibrated" based on the specific circumstances of the case.

The court acknowledged Yeo's genuine remorse and other mitigating factors, but held that one week's jail was "out of tandem" with sentencing trends, and raised the jail term to 10 weeks.