Sydney's Indian community is mourning the deaths of two women who drowned after being swept off the rocks by a freak wave in the Sutherland Shire. 

The Sydney Malayalee Association has confirmed the identities of the deceased as 35-year-old Marwa Hashim and 38-year-old Nirsha Haris.

Emergency services were called to Cape Solander in the southern Sydney peninsula of Kurnell about 4.30pm yesterday, after a large wave swept three women into the water.

The third woman was able to climb onto rocks and was helped by members of the public back onto the shore.

They had been walking in a group of five people along the rock shelf at the time.

"The Sydney Malayalee Association offers our heartfelt condolence to the bereaved families."

The Malayalee ethnic group originate from the Kerala region of southern India.

Superintendent Joe McNulty, Commander of NSW Police Marine Area Command, also gave his condolences.

"They've gone down there with good intentions to enjoy public holiday on NSW finest coastline, and stepped down to a wet, slippery rock platform, and ended up being swept off the rocks by freak wave," Superintendent McNulty said.

He said freak waves were common on the rocks where they were walking.

"In that location, there is an extended rock platform that does protrude out into the ocean," Superintendent McNulty said.

He said it was particularly important for safety messaging to be reaching culturally and linguistically diverse communities.

"In particular, if you're not from a strong swimming background, don't go near the edge of the water, view it from a safe distance," Superintendent McNulty said.

"Never turn your back on the ocean. Always be prepared when you're visiting any rock platform, any beach, any location, where there's large waves are to be careful."