By Tuvan Gumrukcu and Gulsen Solaker
ANKARA (Reuters) - Turkish authorities ordered the formal arrest of nine staff members of a leading opposition newspaper on Saturday and detained more pro-Kurdish officials, widening an anti-terrorism probe that has drawn condemnation from the West.
The arrests, a day after the co-leaders of the pro-Kurdish opposition Peoples' Democratic Party (HDP) were jailed pending trial, are likely to spark more concern among Turkey's allies about President Tayyip Erdogan's intolerance of dissent.
More than 110,000 officials, including judges, teachers, police and civil servants, have been detained or suspended following a failed coup in July. Erdogan's critics say he is using the coup as a pretext to squash the opposition. Ankara says the crackdown is necessary to root out terrorists.
Authorities ordered the formal arrest pending trial of nine executives and journalists from the secularist Cumhuriyet newspaper, including the editor and senior staff of the paper, broadcaster NTV and other media reported. They had been detained since Monday.
In addition, nine HDP officials, including some provincial and district heads, were detained in the southeastern province of Adana, a party official said.
The HDP, Turkey's third-largest party, made history last year by becoming the first Kurdish-rooted party to win the 10 percent of the vote required to enter parliament.
Erdogan and the ruling AK Party accuse the HDP of links to the outlawed Kurdistan Workers Party (PKK), which has carried out a violent insurgency in Turkey's mainly Kurdish southeast for three decades. The HDP denies direct links and says it is working for a peaceful resolution of the Kurdish conflict.
On Friday, the co-leaders of the HDP, Selahattin Demirtas and Figen Yuksekdag, were jailed pending trial after being held in overnight raids. Ten other HDP lawmakers were also detained, although some were later released.
The arrests heightened concern among Western allies about the political direction of Turkey, a NATO member and a buffer between Europe and the conflicts raging in Syria and Iraq.
European Union foreign policy chief Federica Mogherini said she was "extremely worried" by the arrests, and raised her concerns in a telephone call with Turkey's foreign and EU affairs ministers late on Friday. The United States expressed "deep concern".
News of the arrests also shook financial markets on Friday, with the lira currency falling to a record low.
Hours after the detentions on Friday, a car bomb killed 10 people and wounded more than 100 near a police station in the southeastern city of Diyarbakir where some of the lawmakers were being held.
Islamic State jihadists later claimed responsibility for the attack, according to the militant group's Amaq news agency.
Istanbul prosecutors have said staff at the paper, one of few media outlets still critical of President Tayyip Erdogan, are suspected of committing crimes on behalf of Kurdish militants and the network of U.S.-based cleric Fethullah Gulen. Turkey accuses Gulen of orchestrating the coup attempt, though he denies any involvement.
Cumhuriyet's previous editor, Can Dundar, was jailed last year for publishing state secrets involving Turkey's support for Syrian rebels. The case sparked censure from rights groups and Western governments worried about worsening human rights in Turkey under Erdogan.
Additionally, 170 newspapers, magazines, television stations and news agencies have been shut down, leaving 2,500 journalists unemployed, Turkey's journalists' association said in a statement protesting against Monday's detentions.
(Writing by Tuvan Gumrukcu; Editing by David Dolan and Stephen Powell)