Image copyright CBS Image caption Debris at one of the church fires in Louisiana's St. Landry Parish

The outpouring of generosity in response to the fire at Notre-Dame cathedral has led to a renewed focus on fundraising for black churches in the United States that were destroyed by an arsonist earlier this year.

The influx of sympathy and money for the churches led to the appeal reaching its target of $1.8m in three days.

On Monday, as French firefighters tackled the blaze at the 850-year-old building, Louisiana resident Megan Romer tweeted her sadness over the cathedral's destruction.

However, she also took the opportunity to divert her followers' attention to three other churches devastated by fire that did not have billionaires queuing up to save them.

"If you are going to donate money to rebuild a church this week, I implore you to make it the black churches in St. Landry Parish," Ms Romer wrote.

She was referring were three historically black churches in Louisiana that were subject to arson attacks in late March and earlier this month. St Mary Baptist Church, the Greater Union Baptist Church and the Mount Pleasant Baptist Church were razed to the ground.

When Ms Romer wrote her appeal, the fundraising page of the three churches was far short of its $1.8m goal - with fewer than $100,000 raised.

While acknowledging the huge importance of the French cathedral, she wrote: "Remember that famous history isn't the only history. Imagine the courage it took to build and fill a black house of worship in post-bellum rural Louisiana. And now."

She also reminded people that the parish had been the site of the deadly Opelousas massacre in 1868.

Since Monday, her tweet has been shared more than 37,000 times as word spread all over social media. Influential figures like Hillary Clinton and CNN anchor Jake Tapper pushed the fundraising page to their followers.

Image copyright @HillaryClinton

"The rebuild of Notre-Dame will be well-funded," wrote journalist Yashar Ali, who donated $1,000 to the fund.

On Wednesday, total donations for the three churches passed $1m with more than 18,000 people donating. Later that evening, Ali tweeted the $1.8m goal had been reached, including $20,000 donated by model Chrissy Teigen.

Image copyright @yashar

"It shows that the church is not only fireproof, but it's also faith-proof," Pastor Mason Jack told local news channel News15. "To get calls from New York, and across the country and to show love for our sister churches means a whole lot to us," he said.

Image copyright @LAFIREMARSHAL Image caption Holden Matthews has been charged with hate crimes

All three of the Louisiana fires were started with gasoline and occurred around Opelousas, about 60 miles (100km) west of the state capital of Baton Rouge.

Holden Matthews, 21, a son of a local police deputy was arrested over the fires and has now been charged with hate crimes. He pleaded not guilty during a court appearance on Monday.

During the search for a suspect, Governor John Bel Edwards said the attacks were a reminder "of a very dark past of intimidation and fear".