Volcanic hazards increased Thursday from the middle East Rift Zone eruption of Kilauea that began Sunday inside Hawaiʻi Volcanoes National Park, according to the National Park Service.

The Park Service said lava volume significantly increased Wednesday afternoon and on Thursday continued producing hazardous concentrations of volcanic gasses and vog that may occur along Chain of Craters Road, which is open to Holei Sea Arch.

The eruption is taking place in and around Napau Crater in a remote wilderness area more than six miles from the closest road. Lava viewing is not possible, but the Park Service said lava glow outside of daylight hours may be viewable from open parking and pullouts along Chain of Craters Road.

Park visitors are advised to check the park website, nps.gov/havo, for the best viewing options and times. Visitors are also advised to be prepared for heavy traffic, long lines of cars, limited parking and no restrooms. Parking is permitted only in designated spaces, and not along any roadways.

Because of the possible presence of hazardous volcanic gases, the Park Service urges visitors to use the park’s air monitoring website.

“Hazardous volcanic gases present a danger to everyone, especially people with heart or respiratory problems, infants, young children and pregnant women,” the Park Service said.

If visitors encounter vog, they are advised to roll up vehicle windows, turn the vehicle’s air conditioner setting to recirculate, and leave the area.

With changing conditions, there could be new advisories and park area closures, which are updated on the park’s website.

As of Thursday afternoon, closed areas included Maunaulu Trail and its parking area, Kealakomo Overlook and the surrounding area, Napau Trail and Naulu Trail.