A mother has posted a video clip on Facebook and asked for help identifying the man who attacked her daughter out of the blue in front of the Royal Thai Police headquarters building on Wednesday.
Noppawan Nantakit said her daughter, a third-year university student, had exited the Siam BTS train station and walked towards the nearby police headquarters about 11am Wednesday.
Without warning, a stranger had suddenly hit her on the back of the head with a stick. She had immediately run away without looking back as the man prepared to hit her again. He chased her but the second blow missed. He then turned back and strode off as if nothing had happened.
"Anyone who knows the man in the picture please give information. He is a dangerous person... He had no fear, even though he was just in front of the Royal Thai Police Office," Ms Noppawan wrote.
She added that her daughter sought help at police headquarters, where she was examined and found to be all right.
Deputy police spokesman Krisana Patanacharoen said on Thursday that the victim was Jaruporn Nantakit, 21.
He quoted her as saying she first walked past the man, who was sitting on the footpath. Seconds later he rose up and chased her, and hit her. The woman was only slightly injured and insisted she did not know the man, Pol Col Krisana said.
The assailant was probably in his 30s and appeared to be mentally disturbed.
National police chief Chakthip Chaijinda was informed of the incident and ordered the man's quick arrest, the deputy police spokesman said.