A new report says Massachusetts cities and towns have shed more than 15,000 jobs in the past six years, and pension obligations, health care and borrowing costs will continue to squeeze budgets for the foreseeable future.

The Massachusetts Taxpayers Foundation says municipalities face a total of $45 billion in unfunded liabilities and meeting those responsibilities could divert resources from schools, public safety and other services.

The report said municipal revenues increased 3.7 percent in the 2013 fiscal year — an improvement over levels seen during the recession — yet remained below the average 5.2 percent growth between 1982 and 2009.

State aid to cities and towns increased in fiscal 2013 after three consecutive years of cuts, but the foundation said revenue from property taxes registered the weakest growth rate since 1985.