The CIA has warned its counterparts in Europe of the possibility of terror attacks in several countries, with Paris' sewage system among the suggested targets, a French official said Thursday.

The agency warned that Al Qaeda agents may be planning homicide or bombing attacks in London and cities in Italy, France and Germany, Le Monde newspaper reported. It said the CIA had warned of the possibility of attacks taking place this month.

The French official confirmed to The Associated Press that such a note had been sent. The official said the CIA mentioned "waste water systems" in Paris as a potential target.

However, the warning didn't specify dates or exact sites that could be targeted, and no elements led French authorities to believe there was a concrete plot, the official said on condition of anonymity because of the sensitivity of the matter.

French counterterrorism authorities regularly receive CIA warnings, the official added.

Given heightened concerns about the threat of radical Islamic terrorism, "we can't afford to take the luxury of ignoring it — but it's so vague," the official said.

Le Monde said the CIA intercepted an e-mail on Sept. 11 that raised the possibility of an attack on Paris' sewage system. The newspaper said the author of the e-mail was unknown but that it was addressed to Salah Gasmi, a leading member of Al Qaeda in Islamic North Africa.

In Washington, a counterterrorism official said there was ongoing and "very deep concern" about the potential threat from members of an extremist Islamist cell who escaped arrest in Germany after the highly publicized September arrests there of three senior leaders of the Islamic Jihad Union.

German authorities foiled the trio's alleged plot to attack U.S. and other targets in Germany, but up to 10 others believed to be involved in the organization escaped a subsequent manhunt, the Washington official said. At least one is considered extremely dangerous and is now believed to be in Britain, the official said on condition of anonymity because the subject involves intelligence matters.

Al Qaeda in Islamic North Africa is the new name of a Salafist group involved in an ongoing Islamic insurgency in Algeria that now pledges allegiance to Usama bin Laden's network.

The group has claimed responsibility for a string of recent attacks in Algeria. The No. 2 Al Qaeda official, Ayman al-Zawahri, has called for attacks against French and Spanish interests in that region.