Home sales south of Boston ended the year strong, spurred by continued low interest rates, with prices in some areas beginning to inch up amid tight inventory and strong homebuyer interest.

Sales of single-family homes and condominiums in cities and towns in Southeastern Massachusetts rose 23 percent in the last three months of 2012, according to data from the MLS Property Information Network. The median price for the last quarter of 2012 was $314,452, up 4.8 percent from the same period a year ago, with the average number of days on the market at 121, down 28 days from the same period a year ago.