By Budi Satriawan and Yuddy Cahya Budiman

YOGYAKARTA, Indonesia (Reuters) - Thousands of students staged 'Dark Indonesia' protests in cities across the country on Thursday against budget cuts and other policies of President Prabowo Subianto, fearing they will undermine social support systems and their futures.

Clad in black, about a thousand placard-carrying students in the major city of Yogyakarta marched through a busy thoroughfare yelling out demands for change, four months after Prabowo took office following a landslide election win.

There were protests in other cities, including the capital Jakarta, and Medan on Sumatra island.

'Dark Indonesia' has gained traction on social media to represent concerns about the cuts. Another popular trend, 'Just Escape First', sees people sharing advice on how to escape to work and live overseas.

Herianto, a student leader in Jakarta, said students are protesting cuts in the education sector after Prabowo ordered a cost-cutting drive to free up around $19 billion that can be used to fund his policies, including a school lunch plan.

"Indonesia is dark because there are many policies that aren't clear to our society," Herianto, who like many Indonesians goes by one name, said.

"The cuts are designed to plug a hole in the free meal programme expenses. Education is one of the things that could be impacted. Students are so angry."

Prabowo's office has said the funding changes would not affect the education sector and teacher welfare, but with ministries cutting back a wide range of spending there are concerns that it could disrupt government services.

The students were also demonstrating against the military's move into civilian roles and a lack of subsidised cooking gas.

Prabowo remains broadly popular across the sprawling country, with his approval rating near 80% in surveys conducted by independent pollsters, including one last month by research firm Indikator Politik Indonesia.

The demonstrations were the biggest since last August, before Prabowo took office, when the parliament shelved plans to revise election laws after thousands of protesters took to the streets, setting fires and facing down tear gas and water cannon.

(Reporting by Budi Satriawan in Yogyakarta and Yuddy Cahya Budiman, Ananda Teresia and Stanley Widianto in Jakarta; Editing by John Mair and Shri Navaratnam)