In the latest positive indicator for the spring housing market, the number of Massachusetts single-family homes put under agreement in March rose nearly 5 percent.

Sales declined in February for the first time in 22 months before resuming their upward trend in March, the Waltham-based Massachusetts Association of Realtors said Tuesday.

Condo sales increased for the 23rd straight month compared with the previous year, rising 9 percent statewide.

Laura Cahill of Re/Max Cahill Properties in Milton said house hunters are thronging to open houses for properties in the under-$600,000 range.

An open house in East Milton Square last week attracted 86 families, Cahill said. The home, listed at $439,000, received four offers, all of them above the listing price.

“Prices are starting to go up, and there’s no question we hit the bottom last year,” Cahill said.

In the past 12 months, inventories of single-family homes for sale have declined 28 percent statewide, and condo inventories have dropped nearly 33 percent.

With fewer properties for sale, prices have rebounded.

The median price of a single-family home has increased in Massachusetts for five straight months compared with the previous year. In February, prices rose 9 percent to $278,000, while condo prices rose 13 percent to $257,700.

“A lack of inventory continues, but buyers pushed pending sale activity forward in March,” said 2013 MAR President Kimberly Allard-Moccia, broker-owner of Century 21 Professionals in Braintree.

Pending sales figures are based upon residential properties placed under purchase-and-sale agreements. Such agreements typically result in a closing within three months.

Steve Adams may be reached at sadams@ledger.com or follow on Twitter @SAdams_Ledger.