Paris police shot an unidentified man outside the Notre-Dame Cathedral who attacked a police officer with a sledgehammer, while shouting, " this is for Syria." The attack was reported by Fox News who said it occurred on Tuesday, as the police officer patrolled across the front of the cathedral. The police officer was approached by the man who pulled a sledgehammer out and hit the officer on the head with it. The suspect who was injured by police officers was also was armed with kitchen knives.

Terror Investigation

Authorities in Paris have launched a terror investigation.

It is believed at this time the attacker was working alone. French Interior Minister Gerard Collomb stated, "The attacker was carrying an identity card describing him as an Algerian student."

Gerard Collomb continued by saying, "the suspect charged toward officers who were patrolling the esplanade in front of the cathedral.

Yves Lefebvre, spokesman for the Paris police department was quoted by the Guardian as saying, "when the other police officers saw what happened they shot the suspect."

In recent years, Islamic extremists have launched numerous terror attacks across France.The most deadly attack occurred in Paris on November 13, 2015, which left 137 dead and many people injured.

Witnesses at Notre- Dame Cathedral

At the time of the attack, there was an estimated number of 900 people inside the church. The Cathedral and the local area went into lockdown and everyone was told to stay inside. Witness Robbie Thomas said that "everyone was trying to stay calm inside the cathedral," according to Sky News.

He went on to say," everyone was told to raise their hands in the air inside the cathedral. Another witness Lawrence Langner, an American, was reported by The Associated Press to have been across the river from the Notre- Dame Cathedral at the time of the attack. He said that he heard the gunshots and commotion.

Notre- Dame Cathedral

Notre-Dame Cathedral was the idea of Bishop Maurice de Sully and construction began in 1163. The cathedral was not completed until 1345. The Cathedral is world-renowned for its Gothic architecture. Gargoyles are carved along the outside of the cathedral to help with water run off. The cathedral is the biggest Catholic church in the world. The church's largest bell is in the South Tower and is called the Emmanual Bell. The Emmanual Bell weighs 13 tons.

It is also the home of the crown of thrones. The crown of thrones is believed to have been worn by Jesus when he was crucified and it is estimated that the church in Paris welcomes 15 million visitors a year.