A group of policewomen took an unusual approach to crowd control at a May Day protest in Indonesia Wednesday, breaking into a performance of "Gangnam Style" to keep demonstrators happy.

Thousands of protesters in the city of Surabaya in eastern Java cheered with excitement as around 80 female officers did the signature horse-riding dance from South Korean rapper Psy's global hit.

Some of the 5,000-strong crowd even joined in with the officers, who were wearing standard-issue dark police uniforms, sunglasses and caps.

"The crowd went wild. They were so happy, and it was a great feeling to get them excited," Elly Wahyuningtyas, the top female police officer in the area, told AFP, adding they did the dance twice for around half an hour.

"We'd been practising for three days and I think it really helped keep everyone calm and happy."

"They were all so beautiful," she added proudly.

The festive atmosphere was a contrast to other rallies in the country, including one which attracted 55,000 people in Jakarta, where police were faced with angry workers complaining of low salaries and poor working conditions.

Protesters held rallies around the world on Wednesday to call for a better deal for workers.

"Gangnam Style" was a viral sensation on the Internet and in December became the first video to pass a billion views on YouTube.