Six US prisoners have sued authorities to be allowed to see the year's biggest astronomic event, a total solar eclipse on April 8.

The inmates argued in a court filing that their right to religious freedom would be violated if the New York State Prison Service upheld a planned penitentiary lockdown during the eclipse.

"Eclipses, like the one on April 8, are recognized by various religions as special events that warrant gathering, celebration, worship, and prayer," said the submission lodged on March 29.

"(The inmates) have each expressed a sincerely held religious belief that April's solar eclipse is a religious event."

New York's Department of Corrections said in an advisory issued last week that "for facilities in the path of totality, visitation will be canceled."

The path of totality is the area under which the Moon will fully block out the Sun.

The document did not give reasons for the restrictions in the state, one of eleven that will be in the path of totality for the eclipse, according to officials.

The department said in a statement that prisoners in the state's custody would be "returned to their housing units" ahead of the eclipse.

While state "correctional facilities will operate on a holiday schedule with only programs required by statute operating," prisoners will nonetheless be issued with eclipse safety glasses, the statement added.

"The solar eclipse is recognized as an event of great religious significance for Christians, including for Baptists like Plaintiff Travis Hudson and Seventh Day Adventists like Plaintiff David Haigh," the prisoners' lawsuit said.

"A total solar eclipse is also an event of great religious significance for Atheists, such as Plaintiff Jeremy Zielinski," the lawsuit added.

Yet another plaintiff is arguing that the eclipse has a religious significance for Muslims.

The corrections department declined to comment on the lawsuit.

An estimated 32 million people live inside the path of totality, with an additional 150 million residing less than 200 miles (320 kilometers) from the strip, NASA says.

The Perryman Group, a Texas-based research firm, estimates direct and indirect economic impacts of this year's eclipse could reach $6 billion.

This year's path of totality is about 115 miles wide, wider than in 2017. It begins in western Mexico, and arches up through the US cities of Dallas, Indianapolis, and Buffalo, before ending in eastern Canada.

Many schools along the path will be closed or letting students out early, including in Cleveland and Montreal.