The ne (without pas) is used here because of the presence of the verb cesser.

This is not an explétif {not a non-negative ne} where ne does not negate anything, but rather a formal way of negation where ne without pas actually negates a part of a sentence.

The same goes for a couple of other verbs "oser" and "pouvoir", as well as the noun "cesse", as in:

Nous ne pouvons nous permettre une tell folie. {We cannot afford such luxuries.}

Il n‘aura de cesse de faire … {He will not stop doing …}

So your example sentence means:

The inhabitants protest against uncertainty that shows no sign of stopping increasing.

The actual negation "ne cesser / ne pouvoir / n’oser" should not be confused with all the other non-negative ne explétif expressions.

An example of the ne explétif {avant que … ne …}:

Il nous faut agir vite avant qu’elle n‘ait le temps de s’en rendre compte.

= We need to act fast before she pieces two and two together.

Here, the "ne" used as explétif does not negate anything, and therefore can be omitted as well.

The ne explétif tends to be used when a sentence as a whole suggests something bad/gloomy/dark.