[Baltazar]

The problem is that neither MapEditor nor MTA helps removing objects, that are in INTERIORS. Am I doing any mistake or what's the problem? How can I remove any of these items?

[davve95]

All objects aren't deleteable. Maybe all of the interior is stuck on one pice just...

You can get the coordinates to a interior and try to delete it there.

(Point camera at view)

I don't know if you did.