I am forming a large panorama using overlapping areas in several pictures. They are raster images, so my question is, how can I manually erase some parts of them to make a smooth panorama?

It must behave similarly to the Eraser tool in GIMP.

Thanks

You can clip areas in raster images [1] - but, tbh. I'd suggest using a panorama-creation software for a task like this, that would also take care of perspective and color differences. Hugin, for example, is an excellent tool.

http://goinkscape.com/how-to-crop-an-image-in-inkscape/

Thanks Moini for your suggestions.

To answer your question directly, the Eraser tool won't work on raster images. Inkscape is a vector editor, and except for a very few ways, can't edit raster images.