Monday's two visits bring to six the number of escorted tours in the last month, as Baghdad attempts to disprove claims that it is continuing to develop weapons of mass destruction.
They coincide with a report published in London by the International Institute for Strategic Studies (IISS), which says Iraq could build a nuclear weapon within months if President Saddam Hussein was able to obtain radioactive material.
Reporters were taken to the Al-Tammuz reactor in Al-Toweitheh, 40 kilometres (25 miles) south of Baghdad, at which the UN says there has been unexplained activity. The Iraqis claim it is used for pharmaceutical research.
They were also given unprecedented access to the Salman Pak site, 40 km east of Baghdad, alleged by Iraqi defectors to have been used for training Islamic militants.
'No terrorism training'
The former UN weapons inspector Scott Ritter accompanied the journalists to Salman Pak.
He said there was obviously no terrorism training taking place there - a site he said the US was ready to go to war for.
The journalists were shown an old Iraqi plane abandoned in a field, which Mr Ritter said was used by Iraqi security forces to train for rescuing passengers from hijacked planes.
"Any nation that has an airline industry trains people to rescue those who have been on aircraft that have been hijacked," he said.
"If there is a time and a place to go to war I will be there," he said.
"But I am not going to go to war based on a fabrication, especially from politically motivated Iraqi defectors who intend to misuse the tragedy of 11 September by saying somehow those who perpetrated that crime were trained here."
'Completely destroyed'
At al-Toweitheh, reporters saw piles of debris and damaged equipment.
"The site was completely destroyed and it cannot be used for any nuclear activity any more," said Faiz Hussein, the head of the site.
Reporters were taken inside buildings dating from 1994, where they saw the production of medical kits for treatment of kidney and liver diseases, and laboratories which officials said were used for agricultural research.
Iraqi officials have again and again claimed that Iraq does not have the desire or the capability to build weapons of mass destruction.
They say the leadership is to focus on rebuilding the country, which has been hard hit by more than a decade of sanctions.
But there have been no weapons inspectors in Iraq since 1998 to verify or refute the Iraqi claims.