Egyptian security forces arrested a senior editor of the country’s last significant independent news outlet on Saturday, in a new peak to a six-year-old crackdown on press freedom under President Abdel Fattah el-Sisi.

The editor in chief of the outlet, the online publication Mada Masr, said Saturday that a few weeks ago, the authorities had also deported another senior editor, who is an American citizen.

Known for its pioneering investigative journalism and published in both Arabic and English, Mada Masr has remained a critical source of information for intellectuals and activists inside Egypt as well as for researchers and policymakers around the world.

Since 2013, almost every other news organization in the country has come under the effective control of the government.