Media playback is unsupported on your device Media caption Aerial video shows the collapsed envelope of the balloon in a field

A hot air balloon has caught fire and crashed in the US state of Texas, with all 16 on board confirmed dead, the Texas department of safety says.

The balloon came down in fields near Lockhart, about 30 miles (50km) south of the state capital Austin.

Caldwell County sheriff Daniel Law said the basket of the balloon was on fire when emergency crews arrived.

Videos posted by local media suggest the balloon came down near tall power lines, but the cause is not yet known.

The balloon crashed at about 07:40 (12:40 GMT), officials said.

"It does not appear at this time that there were any survivors of the crash," the sheriff's office said.

It is the deadliest hot air balloon crash in the US.

Local resident Margaret Wylie said she was outside her home when she heard two "pops" which she thought was a gun going off.

"The next thing I knew you saw a big fireball go up. I was just praying that whoever was there got away from the thing in time," she said.

Image copyright Reuters Image caption Emergency services were gathered around the charred scene of the crash

Image copyright AP Image caption The hot air balloon came down near power lines

The National Transportation Safety Board will lead the investigation. Erik Grosof, an NTSB official at the scene, said only that there had been "a number of fatalities".

He said the balloon was believed to have belonged to the Heart of Texas Balloon Rides, an Austin-based company that offers trips to see the sunrise with champagne.

A Fox News reporter from Lockhart who is at the scene says contact was lost with the balloon about half an hour into a scheduled one-hour flight.

Two years ago, the NTSB called for better regulation of hot air balloon flights in the US, recommending they should be subject to the same oversight as tour planes and helicopters.

"The potential for a high number of fatalities in a single air tour balloon accident is of particular concern if air tour balloon operators continue to conduct operations under less stringent regulations and oversight," it said.

Governor Greg Abbott asked in a statement that "all of Texas to join us in praying for those lost".

Other deadly hot air balloon accidents

May 2013: Three Brazilian tourists killed and more than 20 other people injured as two balloons collided in the central Turkish region of Cappadoccia

February 2013: A hot air balloon caught fire and crashed in Luxor, Egypt, killing 19 foreign tourists

August 2012: Six people died and another 26 were injured when a hot air balloon caught fire and crashed near Ljubljana, Slovenia's capital

January 2012: A hot air balloon struck power lines and exploded near Carterton in New Zealand, before crashing to the ground - all 11 people on board were killed.

October 2009: Four Dutch tourists died in Guangxi, China, after a hot air balloon caught fire and crashed

August 2001: A hot air balloon touched a power line in south-west France, killing six people