Bow police arrested four people after they secured themselves to one of the towers at the Merrimack Station coal-burning power plant Saturday, police said.

Police were notified just before 5:30 p.m., according to a news release. The plant is operated by Granite Shore Power.

Two scaled the tower to hang a banner, which read “shut it down,” while two chained themselves to the base of the stack, according to a news release from 350 New Hampshire, a grassroots group in support of renewable energy.

The group’s No Coal, No Gas campaign aims to stop the burning of coal and other fossil fuels for electrical generation in New England.

The four were given “several opportunities to leave the property which they refused” over a nearly five-hour period, police said.

The four arrested for criminal trespassing were identified as:

• Dana Dwinell Yardley, 34, of Montpelier, Vt.

• Leif Taranta, 24, of Burlington, Vt.

• Cody Pajic, 23, of Dorchester, Mass.

• Julie Macuga, 30, of Burlington, Vt.

All four were bailed and released. They are scheduled for arraignment next month.