Thailand troubled south remains tense after a series of violent incidents left at least seven people dead.
Security is tight across southern Thailand
The killings came a week after 85 Muslims were killed when a protest turned violent, many of them suffocated while in police custody.
Islamic leaders warned that the tragedy could trigger reprisal attacks in Thailand's mainly Muslim south.
Two state railway workers were shot dead early on Thursday in Narathiwat province, according to police.
In Yala province, a senior policeman was also killed on Thursday, by gunmen on a motorbike.
Late on Wednesday two people were shot dead near their home in Narathiwat, while at least one other man was killed in a separate incident.
Home to most of Thailand's 4% Muslim minority
Muslim rebels fought the government up to the mid-80s
Suspected militants have upped attacks this year, targeting Buddhists
Security forces' response criticised by rights groups
"Buddhists are living in a state of fear because we find that the insurgents are now targeting us," said Pairat Wihakarat, president of
the Teachers Association in southern Thailand.
"They are exacting revenge on innocent Buddhists who have nothing to do with
the ongoing violence," he told the Associated Press.
He was referring to warnings made by Islamic leaders of reprisal attacks for the 25 October deaths of 85 Muslim protesters outside a police station in Takbai, Narathiwat province.
Most of those who died were suffocated in police custody, after being bundled into army trucks.
A senior Buddhist official was beheaded earlier this week in an apparent revenge attack for the Takbai deaths, and there have been several other shootings since the incident.
Warnings that insurgents may try to target Buddhist teachers and students have prompted many schools throughout the south to close until Monday at the earliest.
Muslim militants have tended to target signs of Thailand's Buddhist-majority authorities, such as teachers, local officials and monks.
"Many people have sold their property and taken their children out of the region, but for us we have no choice," Mr Pairat said. "We have no place to run."
Thai Prime Minister Thaksin Shinawatra has ordered an independent panel to investigate the Takbai deaths, but the inquiry has done little to calm fears among Buddhists living in the south.
A militant group called the Pattani United Liberation Organization (Pulo) left a warning message on its website earlier this week
urging Buddhist citizens to leave the Muslim-dominated southern areas, and also threatening terrorist attacks in Bangkok.
The south of Thailand is home to most of the country's Muslim minority, which has long complained of discrimination by the authorities in Bangkok.
Many of this year's deaths have been blamed on Muslim militants targeting local officials, teachers and members of the security forces.