Boeing shares continued to plunge Tuesday as more airlines and regulators clamped down on the company’s 737 MAX planes because of safety concerns.

The stock tumbled 6.2 percent in early trades after British aviation regulators said they were grounding 737 MAX planes and not permitting them to fly in UK airspace.

The move by UK regulators was taken as a “precautionary measure” as British authorities await more details about Sunday’s deadly Ethiopian Airlines crash, which killed 157 people. It was the second crash the 737 MAX was involved in over the last five months.

Tuesday’s drop follows a 5.3 percent tumble on Monday, when the shares gave up $12.7 billion in market value.

The UK is the latest country to halt flights of the jet, following similar actions by China, Indonesia, Australia, Malaysia, Singapore and Oman.

Europe is also said to mulling a ban on the plane, according to a Bloomberg report Tuesday.

President Trump also weighed in on the situation, saying in a tweet Tuesday that airplanes have become “far too complex to fly.”

Boeing acknowledged the decision made by regulators but said Tuesday it has “full confidence in the safety of the MAX.”

“We understand that regulatory agencies and customers have made decisions that they believe are most appropriate for their home markets,” the company said.