Mr. Jawar and Mr. Abiy are political rivals, and both are from the Oromo ethnic group, the largest in Ethiopia.

William Davison, an Ethiopia analyst at the International Crisis Group, a think-tank, said, “Jawar and Abiy have been tense allies over the last year, as they are both popular in Oromia, but have different political priorities. While Abiy broadly wants to move the ruling coalition and Ethiopia away from ethnic politics, Jawar is focused on furthering the autonomy and power of the Oromo people.”

He added, “Abiy has generally tried to govern in the interests of all Ethiopians, but that leaves him open to allegations of neglecting Oromo concerns from activists such as Jawar, who clearly still retain considerable mobilizing capabilities.”

In remarks to Ethiopia’s Parliament on Tuesday, Mr. Abiy made an implicit criticism of Mr. Jawar, who returned to Ethiopia after Mr. Abiy came to power last year.

“When there is peace you are playing here, and when we are in trouble you not here,” Mr. Abiy said, without specifically referring to Mr. Jawar. “We tried to be patient. But if this is going to undermine the peace and existence of Ethiopia ... we will take measures. You can’t play both ways.”

Shimelis Abdisa, deputy president of the Oromia region, which includes Addis Ababa, told a news conference Wednesday night that the police visit to Mr. Jawar’s home had been “a major mistake” that should not have happened.

“It will be investigated and necessary measures will be taken,” he said. “I want to assure you that the federal and regional government will work on the safety of Jawar,” and other Ethiopia exiles who have returned since Mr. Abiy took power.