Protests continued in Boston Thursday morning when four people were arrested after they chained themselves to the entrance of the TD Bank in Downtown Crossing.

The demonstrators, who were protesting the Dakota Access Pipeline, began blocking the entrance around 9:30 a.m., Boston Police Department spokeswoman Maisha Miraj said.

Miraj declined to reveal the identities or charges of the protestors, but said two men and two women were arrested.

Protesters told WBZ they hoped to keep the bank’s entrance closed “as long as possible.”

They circulated fliers about the pipeline that would transport crude oil across the Standing Rock Souix Reservation.

Protestors chained themselves together using bike locks and various other locks, Steve MacDonald of Boston Fire Department, said.

“We did have to cut various locks off. We were on scene for about an hour,” he said.