UPDATED: How'd Greenpeace get on the green roof?

(Fred Chartrand/Canadian Press)

So, how'd that happen?

According to the RCMP, which is responsible for security on Parliament Hill, they're, uh, looking into exactly how a bunch of Greenpeace activists managed to breach security, get onto the green copper roofs of the West and Centre Blocks, then dangle for a little while before unfurling banners demanding Canada take action on climate change.

"For security reasons, I cannot talk about it," RCMP Cpl. Caroline Poulin told reporters.

"The RCMP will be reviewing the incident and we will take appropriate measures."

Ya think?

An Ottawa police spokesman said 20 people have been arrested in connection with the incident and could face charges of mischief. He then praised all units for ensuring the situation was "resolved very quickly." High-fives all around!

The Mounties' red-faced non-explainer news conference comes after firefighters raised a ladder earlier in the morning and removed a banner hung by the activists that read: "Harper/Ignatieff: Climate inaction costs lives."

The protest comes as world leaders and diplomats are gathering in Copenhagen for a United Nations conference on climate change.

UPDATE: From colleague Van Dusen, here's what Public Safety Minister Peter Van Loan's office is saying:

"Security on Parliament Hill is an operational responsibility of the RCMP," Van Loan's office said. "The minister, along with many other Canadians, is interested in the results of the RCMP's investigation."

UPDATE-UPDATE: From colleague Crawford, Greenpeace isn't talking on how its activists managed to get up there, either:
 
"I can't tell you how they got on the roof," Greenpeace spokeswoman Christy Ferguson said with a laugh. "But you know that's something we don't give away."

Also from Crawford: NDP Leader Jack Layton refused to comment on the protesters' tactics, but said Greenpeace "has certainly found an innovative way to show their concern."