* Marks 23rd round of protests
* Close to 10,000 demonstrators in France-ministry
* Macron to unveil policies to quell movement next week (Adds details)
PARIS, April 20 (Reuters) - Clashes broke out between dozens of demonstrators and police in Paris on the 23rd Saturday of yellow-vest protests after authorities warned that rioters could return to the French capital to spark a new wave of violence.
Dozens of black-hooded demonstrators threw rocks at police and some set fire to scooters and trash cans in the center of the French capital, according to Reuters TV footage.
Police responded by firing tear gas and stun grenades. Some officers also marched toward demonstrators to control the crowd and funnel it to Paris' Place de la Republique, where most of the demonstrators were contained in the late afternoon.
As of 1200 GMT, a total of 9,600 people were demonstrating across France, including 6,700 in Paris, the interior ministry said.
This is more than last week's protest, which drew 7,500 demonstrators, but represents only a fraction of the record 282,000 estimated on Nov. 17, the first day of the protests.
As of 1300 GMT, 110 people had been arrested and placed in custody, the Paris prosecutor's office said.
Several demonstrators clearly alluded to the catastrophic fire at Notre-Dame cathedral on Monday, which prompted an outpouring of national sorrow and a rush by rich families and corporations to pledge around 1 billion euros ($1.12 billion) for its reconstruction.
"Millions for Notre-Dame, what about for us, the poor?" read a sign worn by a demonstrator. "Everything for Notre-Dame, nothing for the miserables," read another sign that evoked Victor Hugo's well-known novel.
The city was on high alert after Christophe Castaner, the interior minister, said domestic intelligence services had informed him of a potential return of rioters intent on wreaking havoc in Paris, Toulouse, Montpellier and Bordeaux, in a repeat of violent protests on March 16.
Large portions of the Paris metro network were closed and about 60,000 police were deployed across France, authorities said.
Police also fired tear gas in the city of Toulouse, where thousands of people were demonstrating, including hundreds of motor-bikers holding a large banner asking for President Emmanuel Macron's resignation.
There were about 1,500 to 2,000 people demonstrating in the streets of Bordeaux, according to a Reuters witness.
The so-called Yellow Vest protests erupted in mid-November originally over fuel price hikes and the high cost of living but spiraled into a broader movement against Macron and his drive for economic reforms.
The French leader was due to unveil policies to quell the grassroot movement on Monday, before the blaze at Notre-Dame forced him to cancel the speech. He is now set to make his announcements next Thursday. ($1 = 0.8891 euros) (Reporting by Mathieu Rosemain, Caroline Paillez, Noemie Olive, Anne-Fleur Lespiaut, Yonathan Van der Voort and Helena Williams, Additional reporting by Julie Rimpert in Toulouse and Claude Canellas in Bordeaux, Editing by William Maclean)