Czech Police found knives, truncheons and other weapons on 30 attendees of yesterday's anti-Islam event

Tomáš Hulan, spokesperson for the Prague Police, announced on the official website that police arrested 20 people during demonstrations in Prague on the 17 November holiday on suspicion of assaulting officers and rioting. Police found knives, truncheons and other weapons on 30 people who participated in the Bloc against Islam event at Albertov.

Health care workers provided treatment to several people for injuries sustained during scuffles. Several demonstrations against Islam and refugee reception took place in Prague aiming to criticize the Government over its response to the migration crisis, and there were demonstrations by critics of Czech President Zeman and events in support of migrants.

Police say calm prevailed during the day, disrupted only by isolated scuffles. Officers first arrested three people, one who hit an officer when asked to show identification and is therefore suspected of violence against a public official, another who was unable to provide identification, and a third who threatened suicide and was carrying both cutting and stabbing weapons, according to police.

Various weapons, from kitchen and hunting knives to a handsaw, homemade brass knuckles and pepper spray were confiscated by officers from 30 people who attended the Bloc against Islam event at Albertov, which President Zeman also participated in. "All weapons were confiscated by police officers in accordance with the law and their owners have been detained until all assemblies are over at police stations pending confirmation of their identities," Hulan said.

In the early evening officers arrested three people for disturbing public order who were involved in scuffles near the National Museum. They arrested two people who assaulted the participants in the march on the Office of the Government for the same misconduct.

Hulan said the situation did not escalate until people assembled in front of the cabinet headquarters. The participants in several separate demonstrations then gathered together at the Office of the Government.

Most of the people assembled there had participated in the anti-immigration demonstration that afternoon, attended by roughly 4 000 people. Many participants held green cards that read "We stand by our President".

Tomio Okamura, the chair of the Freedom and Direct Democracy movement, gave a speech. People demanded the Government resign during his remarks.

Police say there were anywhere between 4 000 to 5 000 people in front of the Office of the Government by evening. "After they arrived they broke through the fence that had been temporarily installed to protect the area in front of that institution. The missing fencing was immediately replaced by the officers present," Hulan said.

The assembly was then ended by its conveners and both a city official and police officers called on those participating to disperse. Most people left, but roughly 800 remained at the scene.

When the participants did not respond to police calls to disperse, riot officers were deployed. They first divided the remaining demonstrators into two groups, which they then pushed away from the space in front of the Office of the Government.

According to the police spokesperson, people did not begin to disperse until after that. During their intervention officers arrested 10 people, most of them for using banned pyrotechnics, which Hulan says were thrown at the officers.

Some demonstrators had covered their faces, which is illegal. Emergency medical technicians transported one person to hospital.

That person was not seriously injured, but his eyes had been affected by either pepper spray or a smoke bomb, Jiřina Ernestová, spokesperson for the Prague Emergency Services, told the Czech News Agency. Emergency medical technicians treated another three people at the scene for similarly affected eyesight or for bruising.