Istanbul's opposition mayor on Thursday called for a lockdown in Turkey's largest city after it reported the country's highest number of coronavirus cases and criticised the lack of coordination with President Recep Tayyip Erdogan. Turkey's government has announced measures to contain the spread of the virus from shutting schools, banning mass prayers, suspending international flights to restricting intercity trips.But Mayor Ekrem Imamoglu's demand is likely to put pressure on Erdogan's government which has so far resisted taking stronger lockdown measures. Erdogan has instead urged Turks to adapt themselves to "voluntary quarantine" conditions.The official figures on Wednesday revealed Istanbul with a population of around 15 million is the epicentre of Turkey's outbreak, with 60 percent of nationwide cases and 117 deaths.According to the latest figures released Thursday, Turkey has recorded a total of 356 deaths and 18,135 cases."We are aware that Istanbul has become the epicentre. We have cases and a death toll almost 10 to 11 fold compared to Izmir or Ankara. This shows that if we can control the situation in Istanbul, we can relieve Turkey," Imamoglu told AFP in an interview."When we look at what's being done elsewhere in the world, we believe a two or three-week lockdown in Istanbul will be a measure which will reduce the number of cases, and of deaths."Without a strict lockdown, Imamoglu warned, even if 15 percent of the residents in Istanbul move around rather than stay home, that would represent two million people - the population of some European cities."This has the potential to easily increase the threat."Erdogan's government has stopped short of a full lockdown only banning elderly people aged 65 from going out."This decision needs to be taken by the cabinet, by the president. God willing, a lockdown will be declared," Imamoglu said."The earlier the measures are taken, the more efficient they are. To say 'let's wait a bit' means we don't get what the disease is."Since taking office in June, Imamoglu of the opposition CHP party - widely seen as Erdogan's main challenger for the next presidential elections - has been at odds with the central government. But discrepancies appear more evident during the pandemic.Asked if he communicated his call for a lockdown in Istanbul to Erdogan, Imamoglu said: "I have asked (for a phone call) with the president but I haven't heard back from him yet."Erdogan's office has not commented on talks with Imamoglu, though the interior and health ministries have held talks with the mayor.Imamoglu this week launched a donation campaign tagged "We'll Succeed Together" to help vulnerable populations with cash and essentials.But his campaign was branded "illegal" by Erdogan who himself launched a "National Solidarity" campaign to raise funds, donating part of his salary and urging business leaders and wealthy citizens to contribute.Erdogan blasted Imamoglu's campaign as an initiative which gives the impression of a "state within a state."The mayor said Erdogan's comments were "unfortunate"."The municipality is part of the state."Without naming the Istanbul mayor, Erdogan said Thursday his government would not allow anyone to promote "division rather than solidarity.""No one is above the law in Turkey," he said, taking aim at those who are "trying to dynamite" the government's initiative to raise money. "No one has the right to dilute (our efforts) against the coronavirus".But Imamoglu called for dialogue."We do our best to overcome this (tension). We call, or request meetings," he said. "On our end, we have no problem communicating, even now ... We are obliged to communicate with every part of the state."Agencies contributed to this report.