Major General Auguste Gilliaert arrived from the Congo before the end of the month.
On 27 June General William Platt, advancing with British forces from Sudan, ordered the Belgians to attack the Italian positions if an opportunity presented itself and Gilliaert immediately undertook preparations for an offensive.
The plans for taking Mogi were abandoned and the Belgians were to concentrate their efforts against Saïo, so all but 50 of the soldiers besieging Mogi were redeployed.

I based our chances of success upon continuously keeping aggressive activity along Bortai Brook against Mogi and applying Kitchener's maxim that you can try anything against an enemy who refuses to budge himself.

— Gilliaert
Believing the British pursuit to be closer than it actually was, Gazzera ordered the bridge over the Indina River 40 mi (64 km) east of Saïo to be blown, thereby trapping his forces.
Though still outnumbered, the Belgians decided to carry on with their offensive.
On 2 July, they forced their way over Bortai Brook.
At dawn the next day, the Belgian advance posts opened fire on Saïo and half an hour later, the Belgian artillery went into action.
The Italians responded with heavy counter-battery fire.
A Belgian battalion advanced upon Italian machine gun nests on the two hills that had been occupied since April.
The reserve battalion covered their left flank and Gilliaert dispatched the third battalion under Van der Meersch to the right flank down a goat path that had been mapped by patrols over a fortnight.
Two artillery batteries gave them covering fire.
The Belgians captured the hills and the Italians, being flanked on their left side by Van der Meersch's troops, were unable to make it back to their fortifications atop Saïo mountain.
With the Saïo-Gambela road under artillery fire, they retired to the plains to their right.
Meanwhile, the 2/6th KAR launched an attack on the Saïo-Yubdo road, continuing throughout the next day with success.

The Italians were under the impression that they were facing three Belgian divisions with South African reinforcements.
They also only had about two months' provisions left.
Gazzera radioed to the Allies in Addis Abeba his intentions to negotiate a surrender with the Belgians.
The Belgians were preparing for another assault when at 13:40 two staff cars bearing white flags drove down the mountain.
In them were eight Italian generals, a Catholic priest and Gazzera's chief of staff.
Gilliaert met with them a short distance away from Bortai Brook near Gambela.
They requested that all hostilities south of the Blue Nile cease and that their army be granted the honours of war.
Gilliaert accepted and on 6 July he drove into Saïo to receive the formal surrender of the Italian forces.
Major General Auguste Gilliaert arrived from the Congo before the end of the month. On 27 June General William Platt, advancing with British forces from Sudan, ordered the Belgians to attack the Italian positions if an opportunity presented itself and Gilliaert immediately undertook preparations for an offensive. The plans for taking Mogi were abandoned and the Belgians were to concentrate their efforts against Saïo, so all but 50 of the soldiers besieging Mogi were redeployed.
I based our chances of success upon continuously keeping aggressive activity along Bortai Brook against Mogi and applying Kitchener's maxim that you can try anything against an enemy who refuses to budge himself.
— Gilliaert
Believing the British pursuit to be closer than it actually was, Gazzera ordered the bridge over the Indina River 40 mi (64 km) east of Saïo to be blown, thereby trapping his forces. Though still outnumbered, the Belgians decided to carry on with their offensive. On 2 July, they forced their way over Bortai Brook. At dawn the next day, the Belgian advance posts opened fire on Saïo and half an hour later, the Belgian artillery went into action. The Italians responded with heavy counter-battery fire. A Belgian battalion advanced upon Italian machine gun nests on the two hills that had been occupied since April. The reserve battalion covered their left flank and Gilliaert dispatched the third battalion under Van der Meersch to the right flank down a goat path that had been mapped by patrols over a fortnight. Two artillery batteries gave them covering fire. The Belgians captured the hills and the Italians, being flanked on their left side by Van der Meersch's troops, were unable to make it back to their fortifications atop Saïo mountain. With the Saïo-Gambela road under artillery fire, they retired to the plains to their right. Meanwhile, the 2/6th KAR launched an attack on the Saïo-Yubdo road, continuing throughout the next day with success.
The Italians were under the impression that they were facing three Belgian divisions with South African reinforcements. They also only had about two months' provisions left. Gazzera radioed to the Allies in Addis Abeba his intentions to negotiate a surrender with the Belgians. The Belgians were preparing for another assault when at 13:40 two staff cars bearing white flags drove down the mountain. In them were eight Italian generals, a Catholic priest and Gazzera's chief of staff. Gilliaert met with them a short distance away from Bortai Brook near Gambela. They requested that all hostilities south of the Blue Nile cease and that their army be granted the honours of war. Gilliaert accepted and on 6 July he drove into Saïo to receive the formal surrender of the Italian forces.
Siege of Saïo