Washington ? Surviving leaders of the al-Qaida terrorist network are rallying followers to conduct more attacks despite the arrest of hundreds of extremists worldwide, CIA Director George Tenet said Tuesday.

Some 1,300 people alleged to have ties to al-Qaida have been detained by 70 foreign governments since Sept. 11, Tenet told the Senate Armed Services Committee. But al-Qaida cells in Europe and in the Middle East remain capable of attacks, he said.

“Al-Qaida leaders still at large are working to reconstitute the organization and to resume its terrorist operations,” he said.

Roughly half of the 1,300 remain in custody, said a U.S. official, speaking on condition of anonymity. The rest have been released by the foreign governments.

More prisoners are in U.S. hands in domestic jails, in Afghanistan, or at Guantanamo Naval Base in Cuba.

Other officials have said al-Qaida financial activity and communications have increased in recent weeks, suggesting plans for new attacks. The activity is centered in northwestern Pakistan. Al-Qaida members also continue to seek chemical, biological and nuclear weapons, Tenet said.

In addition, Tenet said U.S. intelligence is watching for alliances forming between disparate Muslim extremist groups. Once divided by ideology, Sunni and Shiite groups may begin working together out of hatred for their common enemies the United States and Israel. Osama bin Laden’s network is largely Sunni, as is the government of Iraqi President Saddam Hussein. Iran and Hezbollah are Shiite.

“The distinctions between Sunni and Shiia that have traditionally divided terrorist groups are not distinctions you should make anymore, because there is a common interest against the United States and its allies in the region,” Tenet said.

Officials said that cooperation of this nature isn’t yet happening to any great degree. However, Tenet noted that Iran “has failed to move decisively against al-Qaida members who have relocated to Iran from Afghanistan.”

Saddam’s offensive

On Iraq, Tenet said the United States believes Saddam has not abandoned his program to try to develop nuclear weapons. The Iraqis are also developing long-range ballistic missiles, even though such work is prohibited, he said.

He also said the Bush administration has not made up its mind on how to proceed against Iraq. Actions including increased diplomatic and economic pressure, covert action, support for insurgents and a full-scale invasion are reportedly being considered.

“Nobody’s made any decisions to do anything,” he said.

Saddam, meanwhile, has embarked “on a political and diplomatic charm offensive,” Tenet said.

Other threats

Tenet, outlining a wide array of threats facing the United States from countries including Iraq, Iran and North Korea, also told Congress that the United States is facing losing its longtime superiority in satellite reconnaissance.

China and India are developing increasingly sophisticated satellites, and sophisticated imagery is also available commercially, Tenet said.

“The advantage we have enjoyed is eroding,” he said.

In other news on Afghanistan, CNN quoted a half-brother as saying his family believes bin Laden is still alive. Sheikh Ahmad, the half-brother who refused to give his family name, said their mother received a call three weeks ago with that information, but he did not say who made the call.