Hundreds of Keystone protesters arrested outside White House

More than 300 people protesting the building of the proposed Keystone XL pipeline were arrested outside the White House on Sunday, according to multiple reports. 

The protesters, many of them college students, began their protest at Georgetown University before making their way to the White House, with some tying themselves to the outer gates. 

{mosads}Police told the Associated Press that 372 people were arrested. U.S. Park Police warned the protesters of arrest if they did not leave the sidewalk in front of the White House. 

Protest leaders estimated that about 1,000 people participated, according to Reuters .

Environmental groups have come out forcefully about the building of the pipeline, saying a spill could have disastrous effects on the environment. 

The release of a State Department report in January triggered a 30-day comment period on the pipeline and a 90-day national determination review. The report found approval of the pipeline likely would not significantly contribute to the increase in greenhouse gas emissions. 

The administration could make a decision on the pipeline after that. After a meeting with the president last week, Oklahoma Gov. Mary Fallin (R) said Obama told a group of governors he would make a decision on Keystone in the next couple of months. 

The administration did not confirm that timeline and has referred questions about it to the State Department, which is ultimately in charge of the decision.