Local military are in “hot pursuit” of between 60 and 70 militants who fled the scene after 16 out of their group were killed when they after stormed a military base in Thailand, authorities have said.

Dressed in army fatigues and armed with AK47 and M16 assault rifles, 100 militants attacked the military base in Narathiwat province early on Wednesday. They were greeted by gunfire from waiting Marines who were reportedly informed of the planned attack.

“Sixteen militants were confirmed dead after the attack,” unit commander Captain Somkiat Pholprayoon told AFP. No military casualties were reported while the number of injured was not provided, The Nation reports.

The attack was one of the most daring attacks in Thailand’s long-running insurgencies.

The government expressed sorrow over the deaths, one of the highest single death tolls in eight years of violence in Thailand’s deep south region.

“The insurgents were uplifted because of a surge in their successful attacks in recent weeks, so this is a significant loss on their side. From now, authorities will certainly have to be very concerned about their retaliation,” Sunai Phasuk, a Bangkok-based researcher for Human Rights Watch said.

Muslim insurgents have been fighting for greater autonomy for the country’s most southernmost provinces, with near-daily shooting and bombings.

Last month, a Muslim teacher was shot dead by two gunmen in the latest attack against education workers who insurgents see as working for the government to impose Buddhist culture on the Muslim-majority region.