Four students were arrested at Waianae High School yesterday morning after a brawl that involved about 20 students, police said.

Michelle Yu, Honolulu Police Department spokeswoman, said three of those arrested were girls and one was a boy.

They were arrested on suspicion of disorderly conduct, taken to the Kapolei police substation and released to their parents.

Officers were sent to the school at about 10:45 a.m. after an anonymous caller reported the fight, police said.

Yu said police were sent to the school again at about 1 p.m. after a second fight broke out.

Police said the school was put into "lock-down mode" following the first fracas.

Officials at the school refused to comment, but Lisa DeLong, superintendent of the district complex area that includes Waianae High School, confirmed that the school "did initiate lock-down procedures."

She could not say when the lock-down ended.

DeLong said "rumors" apparently precipitated the fight but said she did not know what the rumors were about.

"We will be putting extra security precautions in place starting tomorrow to make sure something like this does not happen again," DeLong said.

Bryan Cheplic, spokesman for the city Emergency Services Department, said city paramedics were called to the school at 11:09 a.m. where they treated and released five males and three females who said they were exposed to pepper spray.