Iraq TV also presented the news in a graphic
The first hint of the death of Abu-Musab al-Zarqawi, the leader of al-Qaeda in Iraq, was observed by BBC Monitoring on the Iraqi TV station al-Sharqiya.
The station announced at 0702 GMT that Iraqi Prime Minister Nouri Maliki would soon give a news conference of "paramount importance".
At 0722 GMT the pan-Arab al-Arabiya TV carried a screen caption quoting its correspondent reporting: "Maliki announces the death of Abu-Musab al-Zarqawi in Iraq."
At 0729 GMT al-Jazeera reported that Iraqi TV was quoting the Iraqi prime minister as saying that Zarqawi had been killed. The TV added that "the Pentagon has not thus far confirmed the report".
As viewers waited for the news conference, details began to emerge on other Arabic TV stations.
Al-Zarqawi had been killed during a US air raid, reported al-Arabiya.
"Al-Zarqawi has been killed in air raid north of Baquba," said a screen caption broadcast by Iraqi Patriotic Union of Kurdistan KurdSat TV at 0740 GMT.
Iraqi TV stations broke into their regular schedules at 0741 GMT to bring their viewers the news conference live.
The children's cartoons on al-Sharqiya TV stopped and al-Iraqiya TV interrupted its regular cookery programme.
The scene switched to Baghdad, as Iraqi networks ran the news conference live. Viewers saw Prime Minister Nouri Maliki make the announcement at 0742 GMT:
"Today al-Zarqawi has been killed." The announcement was followed by applause and cheering.
As the news conference continued, al-Iraqiya TV provided a consecutive translation into English.
Pan-Arabic stations combined clips from the news conference with recent footage of al-Zarqawi and reports on his background.
Al-Arabiya cited the US ambassador to Iraq, Zalmay Khalilzad, congratulating the US military but warning that "the killing of Zarqawi will not put an end to violence in Iraq".
Al-Arabiya also quoted Zarqawi's brother as saying that the killing "was expected".
Both al-Jazeera and al-Arabiya dropped their scheduled news bulletins in favour of a continuous coverage of the story, using correspondents from both Iraq and Jordan (where Zarqawi was born).
At 0757 GMT, al-Arabiya was the only pan-Arab channel to carry live a speech by US commander in Iraq George Casey at the news conference, who gave details of the strike and how multinational forces had confirmed Zarqawi's identity.
They had identified the body with fingerprint and facial recognition as well as characteristic scars, he said.
The channel also covered the question and answer session which followed.
Iran's Arabic-language al-Alam TV chose not to give the story continuous coverage, and instead put Zarqawi at the top of their normal news bulletins.
At 0848 GMT, Iraqi Foreign Minister Hoshyar Zebari was the first notable personality to be interviewed on the death of Zarqawi.
Speaking live on al-Arabiya TV, he said "the killing of this terrorist, who topped the list of wanted people, not only in Iraq but on the international level, is a happy day for Iraq, the Iraqi people, and all free people."
"This does not mean at all that we are going to witness an end to killing, violence, terrorism, and terrorist operations," he warned.
He was followed soon afterwards by Iraq's Deputy Prime Minister Barham Saleh, who spoke to Turkish NTV.
"We think that this is a very important victory for the Iraqi people. In fact, this is a great victory for the whole of humanity in terms of the fight against terrorism," he said.
Al-Iraqiyah TV was first to go out onto the street in Iraq to assess the popular reaction to the killing.
All of those interviewed expressed joy at the news
"We consider this a great delight to the people because good has got to prevail," said one.
"We congratulate the Iraqi government on this great achievement because it has cut off the snake's head," said another.
There was also anger from one elderly man who said that "Abu Musab al-Zarqawi deserves to be cut into pieces because he hurt, killed the people and slaughtered the Muslims."
At 1057 GMT, nearly four hours after the first reports, al-Jazeera TV reported that an al-Qaeda website had acknowledged the death of one of its most iconic leaders.
In an urgent screen caption, al-Jazeera TV reported: "Al-Hisbah electronic website used by al-Qaeda confirms death of Abu Musab al-Zarqawi."
BBC Monitoring selects and translates news from radio, television, press, news agencies and the internet from 150 countries in more than 70 languages. It is based in Caversham, UK, and has several bureaux abroad.