About 100 red-shirt members and 80 provincial officials gathered at the station to send her off on a specially arranged train to leave for Si Sa Ket province at 9am with 50 police providing security for her.
About 70 supporters of the People's Democratic Reform Committee came later and stayed 50 metres from the red-shirts waiting to blow whistles at Ms Yingluck, prompting the Surin provincial police to call up another 100 anti-riot police for reinforcement.
The two groups exchanged words, with the United Front for Democracy against Dictatorship calling them over megaphones "traitors" who showed no respect for the rule of law. They were countered by the committee members' megaphones saying the government lacked no legitimacy to administer the country.
Seeing a tense atmosphere at the railway station, the prime minister's advanced security team advised Ms Yingluck and her caretaker cabinet to change plans and go to Buruesee railway station eight kilometres away in the direction of Si Sa Ket instead, with the provincial governor, Surin police chief, former Pheu Thai Party members and a small group of red-shirts moving on to meet up with her.
Ms Yingluck stayed overnight on Tuesday in Surin and faced whistle blowing from a small group of anti-government protesters.
Caretaker Transport Minister Chadchart Sittipunt and caretaker Science and Technology Minister Peeraphan Palusuk were among the passengers on the train ride with her to experience the improved tracks which make the train run at a higher speed of about 100km/h from 60km/h.
She was greeted by red-shirt members and provincial authorities at Si Sa Ket railway station, and an anti-government protester who blew a whistle at her before being taken away by police.
The caretaker prime minister is on a 10-province northeastern trip until Sunday.
Caretaker government spokesman Teerat Ratanasevi denied on Monday that the caretaker prime minister's trip was hastily set to avoid political tension in Bangkok.
"The field visit is not an escape from the protests. It is an official trip which the prime minister has desired for a long time. It is not a campaign for elections either,'' the spokesman said.
Ms Yingluck stayed in Yasothon province for the night on Wednesday.