As the puritanical militia on Tuesday focussed on the consolidation of recent gains, observers see this latest attack as their most formidable attempt yet to capture Mazar-i-Sharif, the only Afghan city outside their control.

``Last year the Taliban learned that over-extended supply lines and over-enthusiasm can have disastrous results,'' a foreign military specialist here said.

``Now they appear to be much more cautious and mature in their attack and are wisely concentrating on consolidation.''

Last year the Taliban suffered two severe defeats trying to grab the dusty city stronghold, despite facing a coalition dogged by frequent bouts of bitter internecine fighting.

In May 1997, the purist Muslim militia joined ranks with Abdul Malik, a former ally of Opposition warlord Abdul Rashid Dostam, who allowed them toenter Mazar-i-Sharif.

But when a deal over power-sharing broke down, Malik returned to the fold of the anti-Taliban alliance to inflict a brutal massacre on at least 2,500 Taliban soldiers trapped in the north.

An estimated 2,000 prisoners captured by Malik also disappeared, later turning up dead in mass graves located in the oil and gas-rich deserts around Mazar-i-Sharif .

``This struck a severe blow to the Taliban morale and recruitment, and now they are exercising extreme caution to avoid being tricked or cut off by the Opposition,'' said a Pakistan-based western diplomatic source.

The second Taliban assault last September avoided deal-making, but the militia were hesitant to be lured into the same maze of narrow streets in which they were cut down in May.

Despite entering the city limits and then being beaten back, the attack did inflict lasting damage on the Opposition, with Dostam returning from exile to fight it out with rival alliance members.

Now the Taliban are again poised to battle forMazar-i-Sharif, following the capture of Dostam's key base and native stronghold of Sheberghan 120 kilometers (75 miles) to the West.

Military analysts here say the fundamentalist Sunni Muslim Taliban will now attempt to consolidate before taking on their toughest rivals who control most of Mazar-i-Sharif, the Shiite Muslim Hezb-i-Wahdat faction.

``Hezb-i-Wahdat have twice ruthlessly beaten the Taliban in the North, and will not be confronted again with such haste unless the Taliban are sure they have a comfortable flank,'' a military specialist here said.

``If these cautious Taliban are satisfied they have a strong launch pad to attack Mazar, then maybe they will be third time lucky.''