The French government put forward plans Wednesday for six-month travel bans on people trying to go to Syria and Iraq to join in the civil war fight. Officials are growing concerned that upon return to Western countries, these supporters will become targets for later terrorist attacks.

Proposal put forward Wednesday by Interior Minister Bernard Cazeneuve include obstacles such as travel bans to deter French citizens that are suspected of trying to join in the war. These measures were announces a few weeks after authorities detained a man on suspicion of killing four people at the Jewish Museum in Brussels in May. This man was thought to be a jihadist returning from Syria with plans to carry out a European attack.

"Recent events show that laws must be adapted to take into account worrying developments," the government said in a public statement.

It is not just European countries showing concern; U.S. Attorney General Eric Holder told American allies to increase efforts in preventing Western-born Muslims from flocking to Syria. The Islamic State, formerly known as ISIS, or the Islamic State of Iraq and Syria, attract many young men from the U.K., France and other European countries to their cause of formic an Islamic caliphate across Syria and Iraq.

Officials estimate that 800 people have traveled from France alone to Syria to fight alongside these Islamist militias. Paris already has laws prohibiting travel between these areas, and in April the government began monitoring websites that promote jihadist groups and facilitate travel from France to the Turkish-Syrian border, a popular gateway to the frontlines.

New measures proposed Wednesday would allow officials to block access to these types of sites as well as the power to search and seize data found on servers located outside France.

"France cannot tolerate that messages calling people to jihad, or glorifying it, are being spread from its own soil with impunity," the government said.