An Islamic militant group that claimed to have kidnapped two French journalists said it would soon decide their fate, according to a message posted on a Web site Friday, and an Iraqi negotiator called the chance for their release "excellent."

The group, the Islamic Army in Iraq, said in a statement that its "legal committee . . . will soon announce its decision" about the two hostages, Georges Malbrunot and Christian Chesnot, who were abducted Aug. 19.

Hisham Dulaymi, an Iraqi tribal leader who has been involved in previous negotiations for the release of hostages, said: "We are working hard to release them."

Meanwhile Friday, a huge fire raged at an oil pipeline near Kirkuk, in northern Iraq, after insurgents detonated explosives in what authorities described as one of the worst sabotage attacks in the area since the U.S. invasion of Iraq, according to the Associated Press.

The explosion Thursday on the line extending from fields southwest of Kirkuk to the oil refinery in Baiji pumped balls of fire and black smoke over the area, the AP reported.

There was confusion about who was holding the two French reporters. Editors at the French daily newspaper Le Figaro, where Malbrunot works, said Thursday that officials believed the hostages had been handed over to a different Sunni Muslim group that was prepared to negotiate their release. But Dulaymi insisted that the Islamic Army in Iraq still held the hostages.

The kidnappers have demanded the French government rescind a law banning students from wearing Muslim head scarves and other overt religious garb in public schools. The law went into effect Thursday.

An aide to rebel Shiite cleric Moqtada Sadr denounced the kidnappings during a Friday sermon in the city of Kufa. "Killing the journalists will not force France to cancel the law against wearing hijab, but it will benefit the enemies of Islam and show Muslims as enemies of freedom," said the aide, Jaber Khafaji.

Tensions were high at the service, held outside the Kufa mosque, which has been closed since insurgents left it as part of a deal made last week.

In the neighboring holy city of Najaf, about 100 Shiites demonstrated, demanding the disarming of Sadr's militia, the Mahdi Army.

One of the protesters, Abu Mahmoud Najafi, 38, said that Najaf's citizens wanted security and stability and that access remained cut off to sacred sites in the city, including the Imam Ali shrine and the cemetery.

In Fallujah, four people were killed and six wounded when shells hit a checkpoint controlled by the Fallujah Brigade, which has patrolled the city since April, according to security and hospital officials and the Associated Press. A Fallujah Brigade commander said the fire was from U.S. tanks; the military had no immediate information on the attack.

Special correspondent Saad Sarhan in Najaf contributed to this report.

Supporters of cleric Moqtada Sadr attend Friday prayers in Kufa, where a Sadr aide in a sermon denounced the kidnappings of two journalists.