Gilles Jacquier of France TV2 is the first foreign journalist known to have been killed in Syria since large protests began there last year, CNN reported. He was hit by mortar fire in a strike that killed a civilian and injured several other people, including members of the press.
French Foreign Minister Alain Juppe called Jacquier's death an "odious act," and demanded an investigation into the slaying, Britain's The Daily Telegraph reported.
"It's up to Syrian authorities to ensure the security of international journalists on their territory, and to protect this fundamental liberty which is the freedom of information," Juppe said.
The rally was one of many held around the country to support the regime of President Bashar Assad. The official government news agency reported that Assad gave an address in Damascus claiming victory and thanking those who support him.
Anwar Malek, who went to Syria with the Arab League monitoring team, said the country is a humanitarian disaster. He said he resigned from the mission because of what he witnessed, including a series of war crimes, the BBC reported.
"The snipers are everywhere shooting at civilians," Malek said. "People are being kidnapped. Prisoners are being tortured and none were released."
Malek accused the Syrian government of orchestrating what the monitors saw in an effort to keep the Arab League from taking action.
"The mission was a farce and the observers have been fooled," he said.
The United Nations Security Council said Tuesday about 400 Syrians have been killed since the Arab League mission arrived in Syria in late December.
Syrian security forces have killed more than 5,000 people since the uprising against the government began in March 2011, the United Nations reported.