Targeting 'Eagle Base'

The conversation was in code, but to trained ears it was easily understood. Picked up by American listening devices on Oct. 16 in Sarajevo, it ranged from the U.S. bombing in Afghanistan to "what the response should be here," a senior Bosnian official told TIME.

U.S. and British targets in Bosnia were mentioned. But it was the resolute sign-off that got listeners’ attention: "Tomorrow, we will start."

Both countries shut down their embassies and branch offices overnight. Using mobile phone card registration numbers, Bosnian police tracked down and arrested both callers — Algerian nationals with Bosnian citizenship. By week’s end three others, also Algerian born, were in custody in a Sarajevo prison, bringing the number of terror suspects apprehended in Bosnia in the past month to at least 10. In the process, NATO uncovered a separate plot to attack "Eagle Base," the airfield used by some 3,000 U.S. peacekeepers stationed in the country. "We are confirming the presence of [bin Laden’s] al-Qaeda network in Bosnia," said a spokesman for NATO-led peacekeepers. The arrests, he added, had "disrupted" the network. "[But] it has not been destroyed. Investigations are continuing."

Direct links to bin Laden, in fact, focus on just one man, the apparent leader of the Algerian cell. Bensayah Belkacem, 41, alias Mejd, worked at a humanitarian agency in the central town of Zenica until his arrest earlier this month. Combing through his dingy rooms, police found two sets of identity papers (Algerian and Yemeni), blank passports, and — in his mobile phone — the number of a senior bin Laden aide, Abu Zubaydah. Like Belkacem, Zubaydah is a veteran of the Bosnian war. Investigators say he is now in charge of screening recruits for al-Qaeda training camps in Afghanistan. According to telephone transcripts, the men discussed the procurement of foreign passports. There was more: Belkacem made 70 calls to Afghanistan between the day of the U.S. attacks and his arrest.

According to a source close to the investigation, U.S. officials are particularly interested in the fact that he repeatedly sought a visa to leave the country for Germany just before Sept. 11.

The other suspects are mostly foreign-born nationals, members of a community of about 200 former mujahedin who came to the country to fight alongside their Muslim brothers during the war and later settled in the interior, often marrying Bosnian women and working at humanitarian agencies. Saber Lahmar, the Algerian who placed the incriminating phone call on Oct. 16, served time in Bosnia for auto theft before being pardoned in 2000. He worked at the Saudi High Commission for Relief, a major agency that has given $500 million to Bosnia. Others, local reports say, worked at the Red Crescent society, Taibah International — a Saudi group — and Human Appeal. Bosnian authorities say they are stepping up surveillance of aid agencies and their staff.

Last week, the U.S. reopened its embassy, located on a busy street in central Sarajevo, noting that with the arrests the specific threat "appears to have passed." They thanked Bosnian authorities for their swift action. But officials tell TIME there are five more alleged terrorists whom police and international peacekeepers are seeking in the rugged hills of central Bosnia. Like that other search under way in Afghanistan, identifying the suspects is one thing. The problem is bringing them in.