Abiy, facing a monumental challenge to his leadership and reformist agenda, dried his eyes with a white handkerchief as mourners wailed around him but he did not speak at the service.

"The crime was not committed by foreign forces but by our own people, and this makes it very painful," Patriarch Abune Mathias of the Ethiopian Orthodox Church said during the ceremony for army chief Seare Mekonnen and a retired general who was killed alongside him.

The crowd of well over 1,000 people was composed primarily of soldiers in military fatigues, while relatives of the dead and government officials wore mostly all black.

Ethiopia has been left reeling after apparently co-ordinated attacks went after top leaders in what officials said was an "attempted coup" in northern Amhara state.

On Saturday, what the government described as a "hit squad" entered a meeting of top Amhara officials and opened fire, killing regional president Ambachew Mekonnen, his top adviser and the state's attorney general.

A few hours later in Addis Ababa, some 500 kilometres (310 miles) away, army chief Seare was shot dead by his bodyguard. The visiting general was also killed.

Analysts have said that while the details are murky, the incidents highlight the political crisis in the country, with Abiy's democratic reforms having unleashed ethnic violence and turmoil as different groups jockey for resources and power.

- Lost forever -

At the Addis ceremony, mourners began wailing and crying out long before proceedings began.

"They have sacrificed a lot for this country," one woman shouted in Amharic. "We love them, but now we have lost them forever."

The entire hall stood as the coffins of the two men were carried in by generals and draped in the Ethiopian flag. The wailing grew louder when a screen showed Abiy, wearing all black and sitting next to Ethiopian President Sahle-Work Zewde, sobbing and bowing his head in prayer.

Soldiers strained to hold back tears as speakers recounted the dead military leaders' long careers and battlefield triumphs. Delivering a eulogy for Seare, a military commander described him as a fearsome fighter who "knew how to win."

"He was very courageous and mentored many soldiers after him," the general said.

"It would be one thing if he were killed in battle or because of some dispute. But what did he do to deserve this?" said deputy chief of staff General Birhanu Jula.

"We will continue the struggle that he started."

A son of the retired general drew applause when he said: "They are heroes and heroes never die."

At the end of the ceremony, Abiy walked up to the two coffins and saluted them. As a brass band played, the coffins were placed in a black van that took them to Bole International Airport.

The men are being flown to Mekelle in their native Tigray region to be buried.

- 'Hidden team' behind killings -

Ethiopian authorities have said the attacks were masterminded by Amhara security chief Asaminew Tsige, who was gunned down by police while on the run on Monday.

Asaminew was only released last year from almost a decade in prison over a 2009 coup plot, in a mass prisoner amnesty that began under former prime minister Hailemariam Desalegn and continued by his reformist successor Abiy.

Analysts describe him as a hardline Amhara nationalist who was likely facing removal from his job over efforts to form a militia and pressing for territory in neighbouring Tigray to be reclaimed.

Abere Adamu, Amhara Police Commissioner, told the state-run Amhara Mass Media Agency (AMMA) on Monday that four senior local officials, including the head of the region's special forces, had been arrested.

He said seven members of what is being described as a "hidden team" orchestrating the attempted coup, were shot dead. Six security officers were killed and four others injured in the operation.

Meanwhile national police chief Endashaw Tassew told a press conference late Monday in Addis Ababa that the Ethiopian government has intensified its large-scale crackdown on the organised coup attempt.

He said members of the "hidden group" were able to convince the bodyguard to kill Seare, without giving further details.

"The impact could have been worse on a national level if we were not able to respond and control the attempted coup shortly after it occurred."

Internet services were down Tuesday across Ethiopia for a fourth consecutive day.