On 15 October 1968, while Nigerian Head of State
Yakubu Gowon was distracted by the anti-tax riots in the west, the Biafran Brigadier Alexander Madiebo encircled Owerri while a unit of Biafran soldiers attacked Nigerian supply convoys attempting to enter the city. The Biafrans were assisted by heavy rain and mud which slowed down supply convoys even further. On 3 December the Biafran 14th Division under Colonel
Ogbugo Kalu and 63rd Brigade under Col. Lambert Ihenacho moved towards Owerri, capturing the villages of
Eziama and Elelem. On 5 December the Biafran 60th Brigade under Colonel
Azum Asoya began the main assault on Owerri, in which over 50,000 rounds of ammunition, 300 mortars, 200 howitzer shells, and 20 anti-tank weapons were fired. The assault lasted for two days but the 3,000-man Nigerian 16th Division under Colonel
E. A. Etuk stayed in their original position, while suffering heavy casualties. The Biafran 68th Battalion under Major Ikeji gained control of a stretch of the Port Harcourt road from Owerri to the Otamiri River, establishing a link with the 63rd Brigade. On 19 December 16 Division regrouped its soldiers and captured the town of
Abiaka, followed by Avu and Afrola on 29 December. On 6 January 1969 the Biafran 60th Brigade captured Umuakpu,
Umuagwo, and Omanelu while the Biafran 68th Battalion under Major Ikeji seized
Obinze; the 68th Battalion attempted to capture Avu but were beaten back by the Nigerian 16th Brigade. By the end of the day, the Biafrans controlled much of the
Port Harcourt road and began planting mines, digging ditches, and laying trees across it in an attempt to block any Nigerian reinforcements from entering
Owerri. On 15 January the Biafran 60th Brigade attacked Owerri and were able to force the 16th Division to retreat across the Otamini Bridge. Instead of pursuing the retreating Nigerians, the hungry and half-naked Biafran soldiers discovered the Nigerians' food and clothing supplies and decided to have their fill. The Nigerian 16th Brigade was able to regroup and made a counter-attack across the Otamini Bridge, causing the Biafrans to retreat. On 24 January the Nigerian government renewed its offensive and began bombing Biafran positions in the area. After five days of continuous air strikes, the Biafrans remained in their original positions; the Nigerian government knew that Owerri was encircled and they couldn't do anything about it. On 7 February both the Nigerian Air Force and Egyptian mercenaries bombed out and completely destroyed the villages of Umohiagu and
Ozu Abam, which prompted accusations by the Biafran Government and its officials of deliberately targeting civilians. The government ordered the Nigerian Air Force to avoid civilian targets but they disregarded this request and continued to bomb towns and Red Cross shelters. In late February, Gen. Gowon visited the 16th Brigade in Owerri and attempted to encourage them to keep fighting until re-enforcements could be sent. On 14 March Nigerian troops attempted to capture the Omanelu-Umuakpu and Elele-Ubimini-Awarra roads but were beaten back by defending Biafran soldiers, leaving them isolated and short of food. On 15 March the Biafran S Division under Major
Timothy Onwuatuegwu made a frontal assault on the 16th Brigade but was forced to halt after suffering heavy casualties. Major Onwuatuegwu placed half of his men under the command of Major
Joseph Achuzie and were able to get within 1 km of the city. Major Achuzie demanded total control of the S Division but was refused by Onwuatuegwu and the two men almost shot each other after drawing their guns. President Ojukwu stepped in and gave Major Achuzie control of the S Division for one week, continuing the frontal assault on Owerri. Achuzie's plan ultimately failed and he retreated after suffering heavy casualties, Ojukwu then immediately restored Onwuatuegwu as commander and began drawing up new plans for invading Owerri. On 31 March the Biafran 14th Division under
Ogbugo Kalu attacked Owerri and secured control over 70% of the city. Biafran soldiers began intercepting radio waves that revealed the 16th Brigade was going to execute all Biafran POWs due to a lack of food. The Swedish pilot
Carl Gustaf von Rosen and his "Biafra Babies" fighter squadron, consisting of six
MFI-9 Junior fighters, constantly hounded Nigerian air drops, making Nigerian food supplies scarce. On 20 April Etuk's second-in-command, Major
Ted Hamman, was shot and killed in Owerri by a Biafran sniper who had managed to get within firing range. On 24 April the remaining 300 soldiers of the Nigerian 16th Division began fighting their way out of Owerri and escaped into Nigerian held territory on 25 April. == Aftermath ==