Local police and the FBI are investigating a suspected arson at a Christian pregnancy centre in the US state of Colorado.

Following the Supreme Court's decision to overturn a landmark abortion ruling on Friday, pro-abortionist mass protests have been taking place across the US.

The ruling means abortion clinics in at least eight states will have to close. Another 13 states with so-called trigger laws will see abortion banned within 30 days.

The fire at Life Choices happened at around 3am on Saturday morning local time.

Photos show the building graffitied with the message "if abortions aren't safe neither are you" and "Bans off our bodies" scribbled on the paving outside.

In a statement to Times-Call, Life Choices executive director Kathy Roberts said they are “devastated” by the attack.

She continued: “What we hope the perpetrators of this act understand is that an attack on Life Choices is ultimately not an attack on a political party or act of,” Roberts said

“It is an attack on those who walk through our doors every day in need of diapers, pregnancy tests, limited ultrasounds, clothing, financial and parenting classes, support, and so much more.  It is an attack on a place that is supposed to be safe for women, men, and their families.”

Local residents are being asked to check their video surveillance footage.

Longmont Public Safety said: "The building sustained fire and heavy smoke damage. At the arrival of police and fire staff, the front of the property had been vandalized with black paint. This fire is being investigated as arson.”