Kabul - The number of roadside bombing attacks in Afghanistan jumped by 50 per cent in the first eight months of the year, according to a top official in the International Security Assistance Force (ISAF).

German General Hans-Lothar Domroese, chief of staff of the ISAF, told Deutsche Presse-Agentur dpa that 1,200 such bombs had been detonated by radical Islamic militia by August this year.

In the same period last year, 800 such attacks had been recorded.

The development was very worrying, Domroese said.

"The rebels have not yet been beaten," he said.

On Wednesday, a German master sergeant was killed as a patrol happened on an improvised explosive device (IED) in northern Afghanistan's Kundus region. On Sunday, another German patrol triggered a roadside bomb, but no one was injured.

The general said that sappers had dismantled 1,300 such bombs this year, compared with 850 bombs dismantled last year.

"That shows clearly that our soldiers are well trained and aware of the danger," he said.

The Taliban rebels have increased their technical capability, Domroese said. They have, for example, reacted to jamming devises used by military convoys to interfere with remote detonation by using more cables and pressure plates to control the devices.

"The Taliban is figuring out how to hit us. But they can't beat us," Domroese said.

Domroese said suicide bombing attacks had increased slightly from the 160 attacks in the previous year. Most of the victims were civilians, the general noted.

Domroese urged more international engagement in civilian reconstruction. The ISAF was committed to the strategy of "clear, hold and build" in order to purge a region of rebels and hold the area under control so that reconstruction can move forwards.

The NATO-led troops were fulfilling their part of the strategy, he said.

Domroese said he expects that by 2012 or 2013, the Afghanistan military will have 120,000 trained soldiers. Reaching that goal was necessary before one could consider reducing NATO's presence, he said. There are currently 63,000 trained Afghan troops. (dpa)