Capitol Police arrested a man Tuesday afternoon who was stopped during a screening at the Capitol Visitor Center because he smelled of fuel and had a lighter with a flashlight and a flare gun, the department said.

A 28-year-old Michigan man, whom police have not named, approached a screening area and placed a backpack and coat on the conveyor belt around 12:20 p.m., the Capitol Police Chief said. J. Thomas Manger to reporters at a conference outside the city. Capitol Tuesday afternoon.

“As soon as his backpack and jacket entered the screening area, the US Capitol Police officers manning that screening area saw what appeared to be something shaped like a firearm,” Manger said.

“They also saw two bottles in the backpack,” Manger said. “While the man was sitting there … one of the officers noticed a faint odor of gasoline, and when they took the backpack off the conveyor belt, they noticed a much stronger odor of gasoline.”

Officers found a flare gun and a lighter, what appeared to be accelerators in bottles, as well as documents the suspect apparently intended to deliver to Congress, Manger said.

The man is in custody and being interviewed by officers, and the department is still determining his motive, the police chief said. Manger said the man’s car was located a few blocks from the Capitol.

“He had some items in his backpack that he may have wanted to set on fire,” Manger said. “It didn’t look like he splashed all over his clothes. Some of his clothes smelled of gasoline, but not all. So it’s unknown at this point what his intent was.”

The visitor center was closed for the rest of the day while Capitol Police investigated.

The Capitol Visitor Center, Library of Congress and Botanical Garden were all open Tuesday despite heightened security across the city. The Library of Congress and the Botanical Garden will remain open to visitors.

Capitol Police put up bike rack barricades ahead of Election Day, as well as fencing on the west side of campus around the area where the Inauguration Day stage will be located. Some businesses in the city have shuttered their windows, and federal and local officials in the District of Columbia are bracing for potential unrest in the coming days and weeks.

“From early voting last week through Election Day tomorrow and through the inauguration, our team has one focus, and that’s how to keep Washington, DC, safe and secure for residents and visitors during election week and more,” the DC mayor. Muriel Bowser told a security press briefing at Metropolitan Police headquarters on Monday afternoon.

Metropolitan Police Department Chief Pamela Smith said the department will work with Capitol Police and other law enforcement to ensure a safe post-election period.

“We are in close contact with the US Capitol Police, as well as our other federal partners, on a regular, daily basis,” Smith said.