Turkish police issued arrested warrants for more than 240 military personnel on Tuesday in relation to the 2016 failed coup attempt in an ongoing crackdown that has seen tens of thousands detained. The arrest warrants were issued in Istanbul and Izmir, with 176 of those affected in active service as soldiers, including a colonel, 100 lieutenants, as well as majors and captains. The suspects are accused of links to the group Turkey holds responsible for the attempted coup, the US-based Muslim preacher Fethullah Gulen's movement. Turkey says Mr Gulen ordered the failed overthrow of President Recep Tayyip Erdogan, but he vehemently denies the charge. The arrested military personnel allegedly communicated with Gulen-supporting imams via pay phones, and 10 civilian suspects were also accused of using the encrypted messaging app ByLock. The app was actually used as a means of communication between Gulenists, Turkish authorities say, and thousands have been detained for having it on their mobile devices. Eight of the suspects have been detained so far. In the northwestern province of Kocaeli, the prosecutor sought the arrest of 17 suspects, including nine current and former soldiers across seven cities, the state-run Anadolu Agency reported. Authorities have detained tens of thousands of individuals since July 15, 2016. The raids show no sign of slowing with almost daily reports of arrest warrants issued despite criticism from Western allies and rights defenders. Critics say the government is using the purge of supposed followers of Mr Gulen to crack down on dissent. Turkish officials stress the raids are necessary to eradicate Mr Gulen's influence in state bodies. Last month, Turkish courts handed life sentences to 24 people it said were involved in the coup. Among the accused, 17 generals were given 141 aggravated life terms each over the deaths of 139 people. The court found that they had "violated the constitution" and "attempted to assassinate the president", state news agency Anadolu reported. Former air force chief Akin Ozturk and Mehmet Disli, the brother of former ruling party politician Saban Disli, who since September has served as Turkey's ambassador to the Netherlands, were among the 17.