Boeing stocks plunged nearly 5 percent on Friday after a fire and a "technical issue" on separate 787 Dreamliners in Britain stoked fresh safety concerns about the new high-tech jetliner.

Dow member Boeing's shares closed 4.7 percent lower at $101.87 in New York, clawing back from a dive of more than 7 percent.

Investor confidence was hammered after a Boeing 787 owned by Ethiopian Airlines caught fire while parked at London's Heathrow airport on Friday.

The fire forced Heathrow, the world's busiest international passenger air hub, to shut down for 90 minutes, but caused no injuries.

A Boeing spokesman said the US firm had personnel on the ground at the airport west of London and was "working to fully understand and address this."

In a separate incident, a Florida-bound Boeing 787 owned by Thomson Airways had to return to Manchester Airport in northwest England after take-off.

Thomson said the flight was turned back as a precautionary measure because of a "technical issue."

The US Federal Aviation Administration said it was aware of the Heathrow fire. "We are in contact with Boeing as they assess the incident," a spokeswoman said.

The incidents were the latest in a series of problems with the cutting-edge Boeing 787, which entered service in September 2011 after three years of production delays.

All 50 787s in service worldwide in January were grounded for about three months due to overheating in its lightweight lithium-ion batteries.

The grounding came after a battery fire on a parked 787 in Boston and, days later, a battery smoke incident that forced an emergency landing in Japan.

Aviation regulators lifted the 787 grounding in late April after approving a Boeing battery fix.

There was no information yet on what caused the fire in the Ethiopian Airways aircraft.

[Image via Agence France-Presse]