Detained Greenpeace activists tell of heartbreak

A Russian Coast guard officer is seen pointing a gun at a Greenpeace International activist as five activists attempt to climb the Prirazlomnaya.

Relatives of two Greenpeace activists detained with 28 others in Russia over an Arctic oil drilling protest have told of their heartbreak over their extended detention.

Tasmanian Colin Russell, 59, and Sydney resident Alex Harris, 27, are among the so-called Arctic 30 charged with piracy and hooliganism over a protest against the oil drilling in September.

Russian authorities have announced they will apply for a three-month extension to their detention.

Mr Russell's daughter Maddy broke down on this morning as she spoke about not having her father back by Christmas during a support rally near the Sydney Harbour Bridge.

"We've had only one call in the whole 60 days since this happened," Ms Russell, 24, said.

"I had a hope in the back of my mind that he would be home in time for Christmas and I don't know what to make of it now."

Ms Harris, who is a UK citizen living in Manly in Sydney's north, has been writing letters to her cousin and housemate Gemma.

"As she writes each letter, each time I read them she becomes stronger and stronger," Gemma said.

As part of a global day of solidarity, about a hundred people gathered in Hickson Road Reserve holding up big white letters that spelled out "Free the Arctic 30".

They also released 30 doves, one for each person detained.

- AAP