HONOLULU -- More than 154 people were stung at Waikiki beaches on Wednesday, according to emergency officials.

Wednesday was the first major influx of the monthly invasion.

Lifeguards said that nearly 300 jellyfish washed on shore.

In Waikiki alone, 164 people were stung. Another two people were stung at Hanauma Bay and one more person was stung at Makai Pier, according to a Emergency Medical Services spokesman.

Paramedics took a 15-year-old girl and a 16-year-old boy to Straub Hospital and Clinic in serious but stable condition.

Jellyfish usually invade south shore beaches when they mate, seven to 10 days after a full moon.

The jellyfish can cause a painful sting that can be dangerous for those who are allergic to the toxins. Officials said that pouring vinegar over the affected areas can help ease the sting.

Anyone who suffers breathing problems, muscle spasms or constant pain should get immediate medical attention, ocean safety officials said.