Rome, Jumada I 24, 1437, March 04, 2016, SPA -- The number of migrants stranded in Greece as a result of border closures in the Balkans could more than triple over the next six weeks, a senior official from UN Refugee Agency UNHCR warned on Friday, according to dpa. "As we are now, by the middle of April we are likely to have 100,000 people in the territory of Greece," UNHCR Assistant High Commissioner for Operations George Okoth-Obbo said in Rome, warning of a "humanitarian crisis" requiring international mobilization. Okoth-Obbo was speaking at a conference held by the Organization for Security and Co-operation in Europe (OSCE), a Vienna-based European security and democracy watchdog. In a separate written statement, UNHCR calculated the number of migrants currently stranded in Greece at around 30,000, including a third at the Idomeni border point with Macedonia, and described the situation as "quickly deteriorating." "We are running out of time, and strong leadership and vision are urgently needed from European leaders to deal with what is, in my view, a situation that can still be managed if properly addressed," UNHCR chief Filippo Grandi said in the statement. --SPA 22:18 LOCAL TIME 19:18 GMT www.spa.gov.sa/w