ABUJA (Reuters) – Nigeria’s President Muhammadu Buhari on Wednesday chaired his first cabinet meeting since returning from sick leave in Britain this month.

Buhari returned to Nigeria on Aug. 19 after more than three months in London for treatment for an undisclosed ailment.

He has kept a low profile and last week canceled a cabinet meeting, raising concerns that the president, criticized for inertia by his opponents, was returning to his former ways, when he worked from home and missed weekly cabinet meetings.

The refusal to disclose details of Buhari’s illness has caused speculation about whether the 74-year-old is well enough to run Africa’s most populous country and biggest economy.

He had reduced his working day to a few hours after returning to Nigeria from his first stint of medical leave in Britain on March 10, diplomats and government sources said at the time.

Since his return this month, Buhari’s office has been releasing a flurry of photos and statements from the president’s engagements, like meetings with his vice president, heads of the military and economic ministers and the central bank.