QUEBEC CITY - Quebec's student protests last year cost taxpayers $90 million in police overtime, repairs to ransacked schools and extra security measures.

Universities and colleges will foot much of the bill but will be compensated for 50% of their extra costs from the months-long protest, sources tell QMI Agency.

Universities have had to pay $13 million in additional salaries to instructors after the spring 2012 semester was cancelled. Increased security measures and administrative costs added $4 million.

Community colleges were forced to add the equivalent of 180 full-time teachers, at a cost of $30.5 million, after the spring semester resumed in September.

Daily demonstrations paralyzed parts of downtown Montreal as tens of thousands of students protested planned tuition hikes under the Liberal government.

The social unrest prompted Jean Charest to call an election for September, which his party lost.

The total bill for police interventions, including riot police deployments, was $29.6 million.