CSS center images by only changing image properties

I have automatically generated HTML (almost impossible to change it because it is generated by a third party library) that can generate this kind of HTML

<p>
<img src="...">
<img src="...">
</p>

It produces something like this screenshot:

I would like to be able to center the 2 image horizontally (here there are 2 but we can I have 1 or more).