Hundreds of international flights were delayed Monday in London as activists chained themselves together to challenge Heathrow, Europe's largest airport. Thirteen activists from the group Plane Stupid breached the perimeter fence and proceeded to the northern runway in a move to protest a plan to expand the airport's infrastructure.

The delay caused several hours as police struggled to remove the protesters from the scene. After cutting a hole in the fence, the activists were found sprawled on the tarmac and secured with arm locks to prevent authorities from hauling them out. A police officer was quoted as saying, "You are causing severe disruption and it will be in the millions of pounds because it will take us a while to remove you," in an MSN report. The protesters were then arrested and will be charged with Aviation Act offenses, according to US News.

Last month, the Airport Commission released a report recommending to build a third runway in order to increase Heathrow's capacity, one of London's five airports that collectively accommodate 73.4 million passengers. This is a controversial issue that currently divides Prime Minister David Cameron's government, MSN has learned. Authorities have been expecting the study as Britain contends with an increase in yearly aviation traffic. Environmentalists and residents have expressed their opposition to the plan, raising the climate change issue with the claim that the expansion will make it harder to reduce air pollution and emissions, according to The Independent.

"This would massively increase carbon emissions exactly when we need to massively reduce them, that's why we're here," said Ella Gilbert stressing that "we want to say sorry to anyone whose day we've ruined, and we're not saying that everybody who wants to fly is a bad person."

Many passengers, whose flights were delayed, were not as understanding. "It's affecting an awful lot of people's lives. I'm not one bit impressed. They should be shot with rubber bullets," Louise Rogers told The Independent.