ISTANBUL — Turkey’s health minister said the coronavirus infection rate was stabilizing, showing the fast-spreading contagion may be under relative control, while the head of an independent medical group said the scale of the outbreak remained unclear because a majority of virus-related deaths were not being counted.

Turkey experienced its deadliest day so far after 115 people died, pushing the death toll to 1,518, according to a post on Twitter by Health Minister Fahrettin Koca. There were 4,281 new cases, which is roughly in line with or even slightly fewer than the daily cases confirmed since April 8, even as testing has nearly doubled over the week. Total cases now stand at 69,392.

“The rate of the increase in case numbers, as well as patients needing intensive care or respiratory support, is on a stable trajectory,” Koca said in the post. Late on Tuesday, he told a news conference the infection rate was leveling off after Turkey saw its fastest rate of transmission last week, the fourth week of the outbreak. “Under the current conditions, we are in the position of beginning to bring the virus’ transmission rate under control,” Koca said.

However, the World Health Organization warned Tuesday that Turkey and Britain still faced an acceleration in new cases, even as other European countries with large numbers of patients are beginning to see a respite. Turkey confirmed its first case of COVID-19 on March 11.