AS Serb shells rained down on Sarajevo with thunderous booms the past two days, walls trembled, glass rattled, and civilians hid.
But a new, strange sound was heard. With thunderous cracks, dozens of mortars smuggled into Sarajevo fired back at Serb tanks and artillery in the hills above the once-defenseless city. UN officials say that the Bosnian Muslims are giving as good as they got. "There were clearly more outgoing than incoming where I was," one UN official says.
The impressive display of newfound Bosnian firepower shows the transformation of the Muslim-led Bosnian Army from a ragtag militia to a well-organized fighting force. After three years of war, Serb snipers still menace Sarajevo streets, but deadly Muslim snipers now strike back.
"Now the Bosnian Army is much stronger than it was even a year ago," says Adis Besic, a young Bosnian Army veteran on crutches. "On my street there are some artillery weapons. When I hear that we are sending the Serbs a grenade, it makes me feel so good."
The fighting in Sarajevo is a resumption of sporadic Bosnian Army attempts to take two key supply roads that run between Serb-held parts of the city and the Serb stronghold of Pale, 13 miles to the southeast. Despite some temporary Muslim advances, Bosnian Serbs still control the roads.
An international arms embargo, weapons from Iran, and cash from other Islamic countries has allowed the Bosnian Army to equip itself with 82-millimeter mortars and other light-artillery weapons.
A once inept and inexperienced officers corps is now using their almost 2 to 1 numerical superiority to stretch out Serb forces that have nearly three times as many tanks and artillery pieces as they do.
"It's almost a Maoist strategy," says a UN official in central Bosnia. "You make small strikes all over the country and keep your opponent off balance, which lowers morale, and it's working."
SHORTAGES of fuel are also hurting the Serbs. "Time is on the side of the Bosnians," says the senior UN official. "I think the Serb military capabilities are gradually deteriorating."
UN military officials say some Serb areas around the city may be under siege from Muslim forces trying to cut the supply roads they depend on.
Bosnian morale - or bravado - appears to be steadily improving. On a Sunday night in Sarajevo, young men dressed in new fatigues kiss their girlfriends goodbye. Each toting his own AK-47, they board a bus headed for the city's front lines. Three years ago men dressed in civilian clothes and units of 10 men were forced to share one rifle.
"Now, we have more weapons, especially artillery," says Sakib, a young Bosnian Army soldier walking the streets of Sarajevo in a new uniform. "We attack in small groups and can find the holes in Serb lines in the hills."
Sakib and other Sarajevo residents say they were not upset by having Bosnian mortars deployed in civilian neighborhoods. But UN officials criticized the tactic, which can lead Serbs to return fire to the area and kill civilians. "The Bosnians have plenty of rural land they could target the Serbs from," says the UN official.
As Western media have focused on UN hostages and events in Sarajevo, three different Muslim army corps quietly launched an offensive two weeks ago to capture a key route linking the Muslim strongholds of Zenica and Tuzla in central Bosnia. An attempt to capture the route last year failed. "I suspect this time they're going to be able to accomplish it," says the senior UN official.
But UN officials warn that a possible shift in military momentum to the Bosnians could quickly be lost if an attempt to break out of Sarajevo fails. Instead of stretching the thinly manned Serb forces out, the Bosnian Army would allow the Serbs to concentrate their firepower on a 12-mile corridor the Bosnians would have to take control of to free the city.
"That would be playing to the Serbs' strength," warns the UN official. "They've got to resist the emotional pull to try to break out."
But Besic, the young disabled soldier dressed in jeans, a T-shirt, and spectacles, disagrees. If the international arms embargo is lifted, as proposed by US Senate majority leader Bob Dole, the Bosnians can easily win the war.
"Sarajevo is the most important point in Bosnia. Whoever controls Sarajevo controls all of Bosnia," he says. "We don't need American soldiers, we just need their guns."