Turkish police are investigating dozens of social media users for allegedly spreading the rumor that President Recep Tayyip Erdogan had died.

Police said on Wednesday that “manipulative” messages were posted under the Twitter hashtag #olmus, which means “has apparently died” in Turkish, according to a written statement. Thirty people suspected of posting “lies” have been referred to the judiciary for investigation, the statement said. 

The Turkish leader’s health became a hot subject on social media after a short video clip purportedly showing him walking with great difficulty went viral on Friday. Another video in July showed Erdogan dozing off for a few seconds during an address to members of his ruling AK Party, unleashing speculation that the 67-year-old president might be ailing. 

Aides have posted videos of Erdogan playing basketball and other sports to dispel what they say is pure speculation. On Wednesday, spokesman Fahrettin Altun shared a 13-second video on Twitter showing a masked Erdogan taking 19 steps away from a black limousine outside the presidential palace, followed by a military officer in line with protocol. 

The video title read: “Trust for friends, fear for enemies.”