Reuters, Washington :US President Barack Obama on Tuesday pledged US assistance to his Turkish counterpart Recep Tayyip Erdogan for the investigation into last week’s attempted coup, the White House said.During a phone call, Obama “strongly condemned” the violent uprising and “urged that the investigations and prosecution of the coup’s perpetrators be conducted in ways that reinforce public confidence in democratic institutions and the rule of law,” it said in a statement.Obama “lauded the Turkish people’s resolve against this violent intervention and their commitment to democracy,” the White House said.”President Obama made clear that the United States is willing to provide appropriate assistance to Turkish authorities investigating the attempted coup.”Turkey has launched a massive post-coup purge. The crackdown on military, police and the judiciary has now widened to include the media and schools. Thousands have been detained.The statement did not say whether Obama discussed with Erdogan Turkey’s request to extradite US-based Muslim cleric Fethullah Gulen, Erdogan’s bitter foe who the Turkish government alleges was linked to the coup attempt.Turkish authorities earlier on Tuesday scrapped all TV and radio station licenses linked to what they called the “Fethullah Terrorist Organisation,” the government’s derogatory name for the Gulen movement.Last week’s coup bid was the most serious threat to Erdogan since he took power first as prime minister in 2003, and saw rebel troops close down bridges in Istanbul, parliament bombed from the sky and protesters shot in the streets.Meanwhile, Turkey has suspended 900 police officers in the capital Ankara on suspicion they have links with an Islamic movement headed by a U.S.-based cleric the government says masterminded a failed coup, an official said on condition of anonymity.Turkey has stripped tens of thousands of public-sector employees of their responsibilities since a July 15 attempt by a faction within the military to overthrow the government. Thousands more have been detained and face prosecution.