By Souhail Karam

RABAT (Reuters) - An international human rights group urged Morocco on Monday to investigate accusations that police tortured pro-democracy activists to force false confessions.

Coinciding with the visit of a U.N. torture investigator for a rare fact-finding mission in Morocco, U.S.-based Human Rights Watch (HRW) said five activists convicted last week may have been forced by violence to confess to crimes.

"The court sent protesters to jail on the basis of confessions allegedly obtained under torture, while refusing to summon the complainants to be heard in court," said Eric Goldstein, HRW's deputy Middle East and North Africa director.

U.S. Secretary of State Hillary Clinton said last week that Morocco could be a regional model after it managed to contain Arab Spring protests with reforms. But she urged Rabat to reform the courts, make government more open and respect human rights.

Last week, a Casablanca court sentenced five activists - arrested at a protest in July against high prices - to between eight and 10 months in prison for, among other things, "unauthorized gathering and insulting the police".

HRW said the activists denied the charges and said the police had tortured them.

It was the latest verdict against pro-democracy activists of the February 20 Movement which led Arab Spring protests in Morocco. Activists have been jailed for protesting, insulting or clashing with police.

Last week, a network of 18 Moroccan human rights organizations said rights have declined despite the adoption of a new charter proposed by the ruling monarchy last year at the height of street protests.

"Morocco can guarantee fair trials only when courts seriously investigate allegations of coerced confessions and dismiss as evidence any confessions the police obtained improperly," HRW's Goldstein said.

HRW's statement came at the start of a week-long visit by Juan Mendez, the United Nations special rapporteur on torture worldwide.

Mendez was invited by Rabat "to assess improvements and identify remaining challenges regarding torture and other cruel, inhuman or degrading treatment of punishment" his office said. His visit will include the disputed Western Sahara territory.

"My ultimate task is to engage with decision-makers and key actors to help the authorities uphold the rule of law, promote accountability for past abuses and allegations of torture and ill-treatment, fulfill the right of reparations for victims, and to ensure that alleged perpetrators are held responsible in conformity with international law," Mendez said.

(Editing by Robin Pomeroy)