Suspected Islamic insurgents opened fire on a school bus in Thailand's restive south on Monday, killing two paramilitary rangers and wounding three teenage students, police said.

The bus was taking 10 students — aged from 13 to 18 — home from a school in Pattani province's Nong Chik district when an unknown number of assailants opened fire from a hiding place on the roadside, said police Maj. Gen. Kririn Inn-kaew.

Two paramilitary rangers who were providing security for the students were shot and fell from the bus, Kririn said. He said the assailants continued to fire at the rangers, killing them and then taking their guns.

Three female students, all Buddhists, were wounded and taken to a hospital, Kririn said. There was no immediate word on their condition.

Kririn said initial investigations indicated the assailants were targeting the rangers.

Thousands of government-hired paramilitary rangers have been deployed in Thailand's southernmost provinces of Pattani, Yala and Narathiwat. The military has recruited local Muslims and Buddhists to join the army-trained units, hoping their familiarity with the geography and people will give authorities an edge over insurgents.

But many Muslims hold a deep hatred against the low-paid rangers, accusing them of abuses and human rights violations in the area.

More than 3,000 people have been killed in the predominantly Muslim southern provinces since early 2004, when a separatist movement flared after a lull of more than two decades.

The government has made little progress in curbing the violence despite the presence in the south of nearly 40,000 police and soldiers. Drive-by shootings and bombings occur frequently.

The school bus attack came two days after suspected insurgents shot up a bustling cafe in Yala early Saturday, killing three customers and injuring four others.

More than 90 percent of Thailand's 65 million people are Buddhists, and many of the country's Muslims have long complained of discrimination, especially in jobs and education.

The southern Thais are the same ethnicity as Malays across the border in Malaysia and share the same religion, culture, food and language.