HOUSTON, Feb. 14 (Xinhua) -- Local police said a powerful explosion hit a facility Wednesday morning in La Porte, about 40 km southeast of Houston, Texas, the United States.

La Porte Police said the incident was a "pressure explosion" with no chemicals involved and no danger to the public.

Some people were being treated for ear pain and dizziness associated with the loud blast, police said, but so far no one has been transported to hospital for treatment.