US President Donald Trump said he was fully informed of the tragic shooting incident at a Catholic School in Minneapolis, Minnesota.

In particular, Trump said that “the FBI has reacted immediately and is on the spot”, adding that the White House would continue to monitor the situation, which it described as “horrible”.

Trump called on the citizens to “pray for all those involved”.

Three people, including the perpetrator, were killed and about 20 injured in a shooting incident at a Catholic school in Minneapolis on Wednesday, according to an US justice ministry official.

According to the authorities up to 20 people have been injured by shots. The same sources described the armed as a man dressed in black rifle. No further weapon has been reported at this stage, while investigations are ongoing.

The incident occurred at the Annunciation Church, where an elementary school is housed with students from kindergarten to eighth grade, according to its website. The first day of the school year was Monday, as a post on the school page on Facebook.

Internal Security Minister Christie Nov said in a post that the DHS is watching the situation and is in contact with local authorities.