(Updates number of vehicles, detail, attack on rebel base)
BAMAKO, Jan 22 (Reuters) - Tuareg rebels in eastern Mali abducted a group of European tourists on Thursday, a senior Malian military officer said.
He told Reuters the tourists, whose precise number and nationality were not immediately known, were abducted at Menaka, near the border with Niger.
"The tourists were in three vehicles in Menaka when they were intercepted by a group of rebels," the source said. "We know (the tourists) are European."
The abducted tourists were driven away in two of the vehicles, which the Malian army began to pursue when alerted by eyewitnesses, he said, while another vehicle escaped.
The website of German magazine Der Spiegel reported on Thursday that a group of Europeans including a German woman and a Swiss couple had been abducted near the Mali-Niger border.
Last October, two Austrian tourists were released in Mali after being held hostage in the Sahara for months by Islamic militants.
Thursday's abduction was the worst such incident in the West African desert state since an Islamic rebel group kidnapped 32 European tourists in the Sahara in 2003, holding some of them for six months.
In a separate incident on Thursday, 31 Tuareg rebels were killed when the Malian army attacked a base at Kidal, around 200 km (125 miles) to the north of Menaka, the Defence Ministry said.
The base was under the command of insurgent leader Ibrahima Bahanga, whose group Malian authorities accuse of trying to control smuggling routes in the Sahara.
"One of Bahanga's bases ... has been destroyed by our armed forces," the ministry said in a statement.
In late December, the Malian military said Bahanga's men attacked an army post close to the border with Mauritania, only months after Algeria brokered a ceasefire between Mali's government and Tuareg rebels.
For more than a year Tuareg fighters have attacked army posts and convoys to demand greater rights for their people, but doubts persist about the participation of veteran chieftain Bahanga, who is seen as a rogue element in the Malian Tuareg armed movement.
(Reporting by Tiemoko Diallo; Editing by Daniel Magnowski)