Houston, Feb 16 (IANS): An estimated 5.6 million trees were killed by last year's devastating drought in the US state of Texas, authorities said Wednesday.

The estimates also mean that as much as 10 percent of the state's urban forest was wiped out during the drought, according to Texas Forest Service.

"This estimate is preliminary because trees are continuing to die from the drought," said Pete Smith, Texas Forest Service staff forester who led the month-long survey of the tree mortality. He said the number may not be known until the end of 2012, reported Xinhua.

The dead trees are in populated areas and will need to be removed out of safety concerns. The estimated cost to remove these trees is $560 million, the agency said.

Texas suffered from the longest dry period on record last year, as wildfires raged through the state and water shortages devastated crop production and livestock herds. An estimated over $5 billion were lost due to the drought.