(CNN) Climate change activists shut down traffic in the nation's capital Monday, blocking key intersections across Washington, DC, to bring attention to their cause.

The #ShutdownDC action was part of the global climate strikes young activists have been leading since Friday, to spur government action on the climate crisis.

Meanwhile, in New York, the UN was planning to host its Climate Action Summit on Monday. Secretary-General António Guterres challenged world leaders to share "concrete, realistic plans" to reduce greenhouse gas emissions.

In Washington, reporter Sam Sweeney of CNN affiliate WJLA tweeted that traffic was gridlocked in the morning and police had made some arrests.

Protesters blocked 16th Street Northwest at K Street Northwest. They secured themselves to a boat in the middle of the intersection and were being removed by police a couple of blocks from the White House.