ISTANBUL — Ebru Umar was sleeping in her summer residence on Turkey’s Aegean coast when police arrived at her door and took her away for questioning about two of her tweets that were deemed offensive to Turkey’s president, Recep Tayyip Erdogan.

The Dutch-Turkish journalist, a columnist for the Netherlands’ Metro newspaper, was released the next day but has been barred from leaving Turkey as authorities continue to investigate whether she should be charged for insulting the Turkish leader.

‘‘I thought it was a joke,’’ said Umar, who tweets so frequently she wasn’t even clear which of her missives caused offense. ‘‘I saw three police stations in one night. It’s stupid. This is just intimidation.’’

Umar is not alone. There are nearly 2,000 cases open in Turkey against individuals, including celebrities and schoolchildren, accused of insulting the president, whose zero tolerance for criticism is the subject of a growing litany of zingers in Western mainstream media and comedy shows.

Turkey’s independent media landscape is rapidly shrinking as a result of government-sanctioned takeovers and forced closure. Journalists have lost jobs because of critical tweets. Others are on trial on charges ranging from espionage to making terrorism propaganda. Gag orders are common.

Erdogan, who became Turkey’s first directly elected president in 2014 after 11 years as prime minister, was once hailed as a reformist. In the eyes of supporters, he had done more than any other leader in advancing Turkey’s bid to join the European Union, injected new life into the economy, and came closest to resolving a long conflict with Kurdish militants.

But as he has consolidated power with successive electoral victories, he has backtracked on many EU-oriented reforms and is taking increasingly drastic measures to safeguard his reputation, which took a hit with a corruption scandal ensnaring people close to him in 2013.

The judiciary has been a key instrument in the crackdown on dissent, with Erdogan prosecuting critics not only at home but also abroad.

Press freedom defenders say Erdogan himself triggered this downward spiral. The president has advocated loosening the legal definitions of ‘‘terror’’ and ‘‘terrorism’’ to include anyone — including journalists, legislators and scholars — who voices support for ‘‘terrorism.’’

Turkey’s war on terrorism encompasses three fronts. While being part of the international coalition against the Islamic State group, Ankara has domestic foes of equal concern: Kurdish militants waging a renewed insurgency in the southeast and loyalists of a US-based cleric opposed to Erdogan, who are not known to have used violence at all.

Umar is one of many journalists — local and foreign — facing problems for tackling such issues critically or using social media in a manner that offends the authorities. ‘‘You can’t investigate people for doing their job,’’ Umar said. ‘‘If people feel offended, it’s their problem. Get a life! Get a skin!’’

In a column, Umar lambasted an appeal sent by Turkey’s consulate in Rotterdam urging Turks in the Netherlands to report cases of people insulting Turkey or its leader. Her case is one of many to strain EU-Turkey relations, but concern over freedom of expression is only one of the issues shaping the way Turkey and EU countries deal with each other.

While rights groups and even diplomats have shown up at controversial legal proceedings in Turkey — a move that has earned the foreign envoys public rebuke from Turkish officials — European leaders have largely pulled their punches on press freedom in Turkey.

‘‘In the long term, it is really dangerous to have a country with so many crises . . . so close to the borders where independent journalism would be impossible,’’ said Reporters Without Borders’ secretary-general, Christophe Deloire.