TUNIS, July 21 (Reuters) - Tunisian President Kais Saied said on Wednesday that the military health department will take over management of the health crisis in the country amid a COVID-19 outbreak - an escalation of a battle over powers with the prime minister. Tunisia is struggling to cope with a resurgence of the virus, with intensive care wards full and doctors overburdened by a rapid rise in cases and deaths and a lack of oxygen supplies. Saied"s comments come after Prime Minister Hichem Mechichi sacked Health Minister Faouzi Mehdi on Tuesday amid an exchange of accusations over performance in the fight against the pandemic and the slow pace of the vaccination campaign. Mechichi accused Mehdi, who is close to Saied, of making "criminal" decisions that led to overcrowding and chaos at vaccination centres. But Saied, who is at odds with Mechichi over their respective powers and political alliances, said that violence, chaos and overcrowding in vaccination centers in Tuesday was orchestrated by people within the political system. "The Military Health Department will take over the management of the health crisis in the country.", he said in comments to Saudi-owned broadcaster Al Arabiya during a visit to a vaccination center in Tunis. Tunisia received aid this month from Europe and Arab countries, which included about three million vaccine doses, and field hospitals as it suffers its worst financial crisis ever and it is on the verge of bankruptcy. The North African country has reported about 18,000 deaths and more than 550,000 coronavirus infections since the pandemic began. So far, only 940,000 people have been fully vaccinated out of a total of 11.6 million residents.