Journalists and media organisations have warned that the jailing of three al-Jazeera English correspondents by the Cairo regime was intended to intimidate others from reporting freely on events in Egypt.

The jail terms of between seven and 10 years for Peter Greste, Mohamed Fahmy and Baher Mohamed were met with outrage from veteran correspondents who have reported on the Egyptian uprising and its aftermath.

Jeremy Bowen, the BBC's Middle East editor, said the verdicts and sentencing were a blow to freedom of speech and freedom of expression. "This is also at least partly designed to intimidate other journalists, and to deny the oxygen of publicity to the Muslim Brotherhood," he said.

Ben de Pear, the editor of Channel 4 News, said he was "appalled and deeply worried by the sentences and what they mean for media freedom in Egypt. I think what the Egyptians are trying to do is intimidate the media at home and abroad to stop proper journalistic coverage of events in Egypt. The freedoms that Egyptians fought so hard for in the Arab spring are rubbished by these sentences."

He called for a robust response from the US and the UK, who were "if not acquiescing, still talking to the Egyptian regime."

De Pear added: "As the editor of an organisation that has sent journalists to Egypt throughout the Arab spring, we now have to think hard about how we cover this story. We won't stop doing it, but this presents a new risk."

Many correspondents joined in a torrent of condemnation on Twitter. Sherine Tadros, Sky News's Middle East correspondent who previously worked for al-Jazeera, tweeted: " As a friend I feel incredibly sad, as a journalist I'm scared, as an Egyptian I'm ashamed."

Anita McNaught of al-Jazeera tweeted: "Wrong. Wrong. Wrong. Mad. Wrong. Peter, Baher and Mohamed did nothing to deserve this #Egypt. #FreeAJStaff."

Channel 4's Lindsey Hilsum posted a photograph of herself in Baghdad wearing a gag to signal her outrage.

She told the Guardian: "There is no justice in this verdict. The Egyptian regime has a vendetta against Qatar, which backs the Muslim Brotherhood, so they see al-Jazeera journalists as guilty by association. But our colleagues have done nothing but report as all honest journalists do.

"Every government that cares about freedom of speech should be pressuring the Egyptian government to overturn this absurd verdict and release our colleagues. I am horrified at this travesty of justice."

BuzzFeed's Middle East correspondent, Sheera Frenkel, said the verdict was "a terrifying declaration of intent against all journalists in Egypt. They are telling us that we should toe the line or risk being next. There was nothing presented in that courtroom which we, as journalists, didn't recognise as work we would do ourselves. "The Egyptian judiciary declared journalism a crime today, and found Greste, Mohamed, and Fahmy guilty for doing their jobs."

Sky News said: "The ruling in Cairo today – sentencing our fellow journalists and al-Jazeera staff – is completely unacceptable. We are thinking of all the journalists families and friends at this time and urge the Egyptian authorities to respect freedom of expression and review this ruling."

The National Union of Journalists urged the British government to do everything possible to get the sentences overturned. "This is an outrageous decision and travesty of justice made by a kangaroo court. This is a brutal regime which is attacking and arresting many journalists to attempt to silence them and prevent them from reporting events," said the union's general secretary, Michelle Stanistreet.

Index on Censorship's (IoC) chief executive, Jodie Ginsburg, said: "Today's verdict is disgraceful. It tells journalists that simply doing their job is considered a criminal activity in Egypt. We call on the international community to join us in condemning this verdict and ask governments to apply political and financial pressure on a country that is rapidly unwinding recently won freedoms, including freedom of the press. The government of newly elected president Abdel Fatah al-Sisi must build on the country's democratic aspirations and halt curbs on the media and the silencing of voices of dissent."

At least 14 journalists are currently detained in Egypt and some 200 are in jail across the globe, according to IoC.