(Adds witness accounts, details on the crash)
By Eric M. Johnson
May 10 (Reuters) - Three people were missing after a hot air balloon caught fire over Virginia during a ballooning festival on Friday, said event organizers and witnesses.
One local described hearing people calling for help from the balloon's basket after officials said it appeared to hit a powerline in Doswell about 30 miles (48 km) north of Richmond.
Rescue crews said they were still searching for the pilot, two passengers and any signs of wreckage.
Witnesses posted photos online showing a balloon in mid air with its basket engulfed in flames and a trail of smoke spilling into the sky.
"They were just screaming for anybody to help them," resident Carrie Hager-Bradley told a local NBC affiliate.
Another resident, Debra Ferguson, told a local newspaper she looked up after other balloons had landed safely near her house and heard cries of 'Oh my god' and then saw a surge of flames.
"As soon as we looked up, the thing blew up right there ... it was like a match, poof, and then it was gone," Ferguson told the Free Lance-Star, of Fredericksburg.
The balloon "apparently hit a power line" at 7.30 p.m. local time (2300 GMT) said Federal Aviation Administration spokeswoman Kathleen Bergen.
The balloon was taking part in the Mid-Atlantic Balloon Festival and crashed near a park, organizers said in a statement on their website, quoting Virginia state police.
"No wreckage has been found yet, and there are no confirmed injuries or fatalities," the statement added.
A ground search was under way involving state police, the Federal Aviation Administration, and local law enforcement and emergency workers, officials said.
"State police report that bad weather elsewhere in the Richmond vicinity has grounded air search for the time being," organizers wrote on the website.
The festival was hosting a special "Friday Flights Happy Hour" for a limited audience from 6 p.m. to 9 p.m. local time, according to organizers.
More than 20 hot air balloon teams from across the United States were die to take part in the festival at The Meadow Event Park in Caroline County, organizers said.
A spokesman said the remainder of the events on Saturday and Sunday have been canceled. (Reporting by Eric M. Johnson; Editing by Andrew Heavens)