This article is more than 6 years old

This article is more than 6 years old

Egypt's security forces have detained a team of journalists working for al-Jazeera English, arresting three men in a dusk raid on an office and apprehending a fourth from his home, on charges of "spreading false news" and holding meetings with the Muslim Brotherhood.

The arrests signal an escalation of the crackdown against voices critical of Egypt's military-backed government, in a week in which the Muslim Brotherhood was formally designated as a terrorist organisation and hundreds of its supporters arrested.

Police arrived at al-Jazeera's temporary work suites in Cairo's Marriott hotel on Sunday night, arresting bureau chief Mohamed Fadel Fahmy and veteran correspondent Peter Greste. A freelance producer was also detained.

Greste, an Australian citizen, previously worked with the BBC, CNN and Reuters and won a Peabody Award in 2011 for his work in Somalia. Fahmy is known for his coverage of Egypt's restive Sinai peninsula, the focal point of a military operation against jihadist groups.

A third employee, Mohamed Fawzy, was arrested at his home at about the same time, a colleague confirmed to the Guardian. The interior ministry has accused the journalists of broadcasting "false news" that "damaged national security'", and holding illegal meetings with the Muslim Brotherhood.

The Brotherhood was designated as a terrorist organisation on Christmas Day after an attack on a security headquarters left 16 people dead and more than 100 injured. The government has been unable to provide evidence linking the Brotherhood to the attack. Responsibility has instead been claimed by Ansar Bayt el-Maqdis, a North Sinai-based jihadist group responsible for a number of high-profile attacks on security installations near the Palestinian border, as well as on the Egyptian mainland.

The Qatari-owned al-Jazeera network has faced mounting pressure from the Egyptian authorities since former president Mohamed Morsi was deposed in a military takeover on 3 July. Its Egyptian outlet, al-Jazeera Mubasher Misr, is one of the few remaining channels perceived as sympathetic to the Muslim Brotherhood.

Qatar was a strong ally of the movement and is home to a number of its senior figures who left Egypt in order to escape the military-led authorities' dragnet of arrests.

Although employees of al-Jazeera English, a prominent international broadcaster, had thus far escaped arrest, a number of the network's other employees have been detained, including 25-year-old al-Jazeera Arabic correspondent Abdullah al-Shamy. Family members say the young man has been held in squalid conditions, a fate now faced by thousands of other detainees, mostly Morsi supporters, who have entered Egypt's overcrowded prisons since July.

In 2013, Egypt was among the most prolific jailers of journalists in the world, according to a recent survey by the Committee to Protect Journalists (CPJ). Although press freedom temporarily increased following the ousting of President Mubarak in 2011, it grew increasingly tenuous during Morsi's year in office.

According to Shaimaa Abulkhair, CPJ's Egypt consultant, press freedom has become even more limited under the country's new rulers.

"Today's arrests have big implications for the country's press freedom," she said. "The authorities are willing to move against any channel that is not seen as supportive of the current government."

On Sunday, the US defence secretary, Chuck Hagel, expressed concern about recent developments in Egypt, using a telephone call to army chief General Abdel Fattah al-Sisi to discuss the "balance between security and freedom".