A woman has been arrested after two random assaults in Brisbane city on Monday morning.

City workers Debora Prado and Christina Degn were walking to work near the intersection of Adelaide and Wharf streets when a woman suddenly grabbed Ms Prado grabbed around the throat.

"We were walking down here and talking, and she just grabbed [Ms Prado's neck] and kept going," Ms Degn said.

Ms Prado received small puncture wounds from the alleged attacker's nails, but was otherwise unharmed.

"I just said I'm not going to let her get away, I'm going after her," Ms Prado said.