Have Silencer, Will Recon: Details Emerge in London Terror Arrests Cops: Men pledged allegiance to ISIS, did recon on police station and barracks.

 -- The four men arrested in London on terrorism charges allegedly had a silenced weapon and had conducted "hostile reconnaissance" of a police station and an army barracks, police said today.

A post on the London's Metropolitan Police website lays out a list of accusations against the four men, who were all arrested over the last two weeks, in connection to the charge that they, "with the intention of committing acts of terrorism, or assisting others to commit such acts... engaged in conduct in preparation for giving effect to that intention."

Four men, including 21-year-old Tarik Hassane, nicknamed "The Surgeon," are accused of, among other things, taking an "oath of allegiance" to the brutal Iraqi terror group the Islamic State of Iraq and Syria (ISIS), acquiring a silenced handgun and ammunition, using code words when discussing money or firearms, looking at Instagram images of individual cops, and using Google Street View to conduct "hostile reconnaissance" of a police station and army barracks.

The men had also allegedly downloaded "jihadi material" including issues of the Al Qaeda magazine "Inspire."

A fifth man faces weapons charges for allegedly providing the gun.

All five men appeared in court today for a preliminary hearing in which they only spoke to confirm their names and addresses, according to The Associated Press. Two of the men reportedly laughed as the court read details of their alleged plot.

In a separate post on the MET website today, National Policing Lead for Counter Terrorism Assistant Commissioner Mark Rowley wrote that the MET has made over 200 arrests this year and is running "exceptionally high numbers of counter-terrorism investigations, the likes of which we have not seen for several years."

"These plots are of varied sophistication, from individuals planning to carry out spontaneous yet deadly attacks to more complex conspiracies, almost all seemingly are either directed by or inspired by terrorism overseas," he said. "Public safety is our number one priority and we will always focus our disruption activity against those posing the greatest and most imminent threat. Sometimes this means intervening very early -- essential to prevent attacks, but presenting enormous challenges in securing sufficient evidence to charge."