The bombing raids took place amid a land battle in northern Bosnia, during which Bosnian and Croatian forces, for the first time in months, succeeded in closing the Serb-held corridor across northern Bosnia.
The aircraft were flying too high to be visible but they could be heard clearly. So could the anti-aircraft batteries, pounding away from Brcko, and from the north bank of the Sava river, in Croatia.
Bosnian Serb leaders in Geneva have insisted that their planes, based at the Serbian stronghold of Banja Luka, did not break the UN resolution. But planes did fly over northern Bosnia, and, as neither Croatia nor Bosnia has an air force, they must have been Serbian fighter planes. A Western diplomat confirmed the report of an eyewitness in Banja Luka, who saw planes taking off during the weekend, at a time when Bosnian Serb leaders claimed that their planes were grounded.
Bosnian radio claimed at least 19 people were killed and dozens more wounded over the weekend from repeated bombing raids over Brcko and Gradacac. A reporter from Gradacac on Bosnian radio said 'it was like Hiroshima'.
He described scenes of people running on to the streets of Gradacac to pull the dead and wounded out of the rubble, in spite of the danger they faced of being hit in another raid. He said fresh Serbian troops from the nearby town of Bosanski Brod had joined in the assault on Gradacac, which may be the next Bosnian stronghold to fall to the Serbs.
Bosanski Brod fell to Serbian forces last week, after holding out for six months. The loss of this strategic north Bosnian town was a severe blow to the morale of the Bosnian government in Sarajevo under Alija Izetbegovic. For the Serbs it was one of the biggest military successes during six months of fighting.
At the same time, an intense land battle got under way over the weekend around a second Bosnian-held enclave, at Orasje. Serbian fighters near Brcko said Bosnian and Croatian reinforcements crossed the Sava from Croatia to bolster the stronghold.
The shelling exchanges between the Bosnian and Serbian forces was so heavy that the Serbs closed the corridor of land they hold across northern Bosnia, and which links Serb-held territory in Bosnia with Serbia proper.
Serbian militiary police from Brcko were determined not to let reporters into the town, apparently out of concern for our safety. There could be another reason: the mostly Muslim town is at the centre of some of the most horrific and well-documented accusations of atrocities against civilians.
The reports that Serbian forces have violated the 'no-fly' resolution poses a dilemma for the UN. The resolution envisages only the monitoring of airspace violations, and does not authorise the use of force to stop them. Reports of repeated violations by Serbian planes will strengthen the demands of those countries that favour a new resolution, explicitly authorising force.