MORONI (Reuters) - Troops shot dead two “criminals” in clashes on Comoros’ Anjouan island on Wednesday, a government official said, amid a wave of unrest against constitutional changes.

Protesters have barricaded roads on Anjouan this week, angry at President Azali Assoumani’s plans to extend term limits and end a rotating tenure of his post in a way they say could leave the small island permanently excluded from power in the archipelago.

On Wednesday soldiers shot dead two people and wounded four after clashes erupted between soldiers and a group of masked men, an official from the island’s defense ministry told Reuters, calling the group “criminals acting under the influence of drugs”.

“All are criminals who participated in these unacceptable acts. They have been identified and will face justice,” the official said, speaking on condition of anonymity because he was not authorized to comment to the media.

Another official, from the Ministry of Interior, said soldiers had surrounded the center of Anjouan’s capital Mutsamudu and were preparing to “neutralize” the group.

Politicians on the Indian Ocean islands have called for restraint. Anjouan’s governor Abdou Salami Abdou said he “understood the motives of the insurgents” but called for an end to violence.

In August, Assoumani - from the largest island, Grande Comore - said a June referendum had approved the extension of presidential term limits and an end to the rotating presidency. The opposition called the referendum illegal.

Assoumani plans to compete in presidential polls in early 2019. That would deny Anjouan its turn to occupy the presidency from 2021, as would have happened under the previous system that rotated the post among the country’s three main islands.

Assoumani has been in power since 2016 and would have had to step down in 2021 under the old term limits.

The former military official joins a string of leaders in African countries such as Rwanda, Uganda and Cameroon who have extended presidential term limits or otherwise amended the constitution to remain in power.

“The situation is intolerable, we live with the sound of constant gunshots. We fear being hit by shrapnel. The whole family slept in a cave,” a resident of Mutsamudu, who did not wish to be named, told Reuters.