WASHINGTON (AP) — Sales of new U.S. homes tumbled 5.3 percent in June and the median sales price also slipped, a potentially ominous sign for the U.S. housing market.

The Commerce Department said Wednesday that newly built homes sold at a seasonally adjusted annual rate of 631,000 last month, less than May's revised figure of 666,000. The decline follows solid growth in previous months. New-home sales have risen 6.9 percent so far this year, but builders are starting to wrestle with rising costs for lumber. At the same time, mortgage rates are on the rise and wage growth has been meager, squeezing many would-be buyers.

"Weak June new home sales add more evidence that the housing market is flattening, and may have peaked for this expansion," said Robert Frick, a corporate economist for Navy Federal Credit Union.

Monthly home sales figures can be volatile, but the latest report follows a string of setbacks in the real estate market.

The National Association of Realtors said Monday that sales of existing homes fell 0.6 percent in June, the third consecutive monthly decline. A shortage of listings and rising prices has contributed to a dip of 2.2 percent in existing home sales in the past year.

Last week, the Commerce Department said that ground breakings on new homes plunged 12.3 percent in June to a seasonally adjusted annual rate of 1.17 million, the slowest pace of construction since September 2017.

Home prices have been climbing, yet the median sales price for new home declined last month. The median sales price declined 4.2 percent from a year ago to $302,100, as the proportion of homes selling for between $200,000 and $299,000 shot up last month.

Regionally, there was a 36.8 percent gain in the number of new houses sold in the Northeast. There were declines in the South, Midwest and West. The Midwest recorded the biggest drop, with new home sales falling 13. 4 percent last month.