ANKARA - Turkish police foiled a bomb attack in Ankara on Tuesday, the sixth anniversary of 9/11 attacks on the United States, averting what officials said would have been a disaster for the capital.

Ankara governor Kemal Onal said police had found a van packed with explosives near a multi-storey carpark in a central district of the city of four million. Shops and offices in the area were quickly evacuated.

"The police efforts prevented a possible disaster...It is too early to say who was behind this but the bomb was big and I do not want to think what might have happened if it had gone off," Onal told reporters.

Private broadcaster NTV said police had found about 300 kg of explosives at the scene.

Kurdish separatists, ultra-leftists and Islamist militants have all carried out attacks in Turkey in recent years.

In November 2003, more than 60 people were killed in al Qaeda-backed suicide bomb attacks on two synagogues, the British Consulate and the HSBC bank in Turkey's largest city, Istanbul.

Police threw a wide cordon around the Ankara car-park after finding a suspicious mini-bus. Sniffer dogs were at the scene.

"Police ordered us to evacuate our building. People panicked and started running. Now we are waiting in the bazaar near the car park for permission to return," said Abbas Yuksel, 38, who works for a construction company based in the area.


SENSITIVE DAYS

Onal noted that Sept. 11 and 12 were particularly sensitive days. The world remembers on Tuesday al Qaeda attacks on New York and Washington, while Turkey will mark the anniversary of its 1980 military coup on Wednesday -- a possible focus for leftist groups.

A U.S. air base in western Germany received a bomb threat on Monday evening, prompting a large operation by local police and American forces to secure the site, police said on Tuesday.

The base received a call from a man who spoke in German with a Russian or Turkish accent and threatened to attack the air base in Spangdahlem with bombs. He had at least four accomplices.

In May, a suicide bombing in a central Ankara shopping centre killed at least six people and injured dozens. Turkish authorities blamed Kurdish guerrillas for that attack, though they denied any involvement.

In August a much smaller bomb blast occurred outside a courthouse in Ankara, which is a well protected and normally safe city.

"We will continue our efforts (to make Ankara more secure)," Onal told reporters.