On 4 October 1967, the Nigerian Army's 2nd Division began bombarding Onitsha and continued the assault for eight days, before a 10 boat armada crossed the Niger River into the city.

The occupying Nigerians didn't pursue retreating Biafran soldiers and instead opted to loot and burn the Onitsha market to the ground.

The Biafran 11th and 18th Battalions under Major Joseph Achuzie and Col. Assam Nsudoh formed a pincer and attacked Onitsha from two directions, capturing and killing most Nigerian soldiers.

In December 1967 the Nigerian 2nd Division and the 6th Battalion crossed the Niger River at Idah and began making their way towards Onitsha, finally capturing the city after several attempts.

Homemade Ogbunigwe rocket missiles were launched by the Biafrans at a tanker truck carrying gasoline which caused an enormous explosion destroying many of the convoy's armoured vehicles and killing a large number of Nigerian troops.