BANGKOK — The insurgent group announced its existence with a predawn attack on three Myanmar border guard posts. Hundreds of Rohingya militants, armed mainly with knives and slingshots, killed nine police officers and seized weapons and ammunition.

It was about time, Naing Lin, 28, said of the October attack near his village, Kyee Kan Pyin.

“The government is torturing us,” he said by phone this week. “The aim of the group is to protect our rights. That’s all. They are doing what they should do.”

The beginning of an armed resistance is just one of several developments that are reshaping the conflict over Myanmar’s persecuted Rohingya minority with potentially far-reaching consequences.

The group that attacked the border posts, Harakah al-Yaqin, is believed to have several hundred recruits, substantial popular support and ties to Saudi Arabia and Pakistan, according to a report by the International Crisis Group. Separately, there has been a surge of international humanitarian and political support for the Rohingya cause, mainly from Muslim countries that have cast the Rohingya as the Palestinians of Southeast Asia.