From the Post:
The assault occurred steps away from the greenspace around 11:10 a.m. near 4th Avenue and Union Square East, leaving the victim with a laceration to his head, cops said.
Emergency responders rushed the man to Bellevue Hospital with non-life-threatening injuries, officials said.
The suspect, whom police described as about 5 feet 10 and who wore a black shirt and multicolored shorts, fled eastbound on East 13th Street.
Other media outlets are reporting the same basics at the moment. There isn't a better description of the suspect for the time being... and the motive for the attack is unclear.