Free continuum molecular hydrogen 1–0 S(1) emission line at 2.12 μm extracted from the UWISH2 survey (left). Green contours represent the ALMA continuum emission at 334 GHz. The red square shows the field of view of the observations presented in this work. The green, blue, and magenta squares, labeled from A to E,indicate the position of the powering source candidates of the MHOs, following Froebrich & Ioannidis (2011). ¹²CO J = 3–2 emission distribution integrated between −18 and +24 kms⁻¹ (blue) and between +68 and +107 km s⁻¹ (red) (right). Green contours represent the ALMA continuum emission at 334 GHz. The beam is indicated in the top right corner.