BANGKOK, June 16 (Xinhua) -- At least one sanitation worker was slightly injured in a suspected ping pong bomb attack at about 1:30 p.m. local time near UNESCO office in Thai capital Bangkok.

According to Thai media Komchadluek, the female sanitation worker found a bag which contained a certain object taped up in black before it exploded.

The worker is being treated at a Bangkok hospital right now.

Police is still investigating the incident and some reports say the bomb looked like a ping pong bomb.