These operations coincided with an expansion of the separatist Rwenzururu movement, a rebel group that exploited the collapse of the Uganda Army along the Uganda-Zaire border to secure territory and weaponry for itself.

[7] The Tanzania People's Defence Force (TPDF) and allied rebels captured Masaka on 24 February, followed by Mbarara on the next day.

Nyerere feared international repercussions and condemnation if the TPDF advanced even further, yet ultimately decided to sanction a continuation of the offensive so that "several million people in southern Uganda [would not be left] at the mercy of Amin".

[16] The Ugandan rebels assigned to the Task Force consisted of FRONASA militants under Museveni,[17] though he spent more time dealing with political and administrative issues than military ones[18] and was largely absent from the frontlines in April and May.

In the reorganization period at Mbarara, FRONASA split its troops into colums of 538 which were mainly supposed to operate as guerrillas and auxiliaries for the TPDF.

[21] Journalists Tony Avirgan and Martha Honey argued that the FRONASA forces generally "proved to be next to worthless" for combat and guerrilla missions,[22] a charge denied by Museveni who claimed that his followers were eager and comparatively effective in their auxiliary role.

[23] In addition to the FRONASA troops accompanying the Task Force, Kikosi Maalum militants loyal to Obote also operated on the western axis.

[22] Museveni later stated that the two UA commanders who gave the Task Force a "lot of trouble" were Bernard Rwehururu and Yorokamu Tizihwayo.

[25] According to Museveni, TPDF Task Force soldiers believed that the Uganda Army troops opposing them were supported by Libyans and Palestinians.

[28] Though Libyan soldiers and Palestine Liberation Organisation (PLO) militants were actively involved in the war on the side of the Ugandan government,[30] it is unclear whether they were ever present in the western theatre.

Though poorly armed, the Rwenzururu movement maintained control of many rural areas in the mountains during Amin's rule, had set up a sort of parallel state, and raised its own taxes.

[31][32] It mainly consisted of Konjo and Amba militants led by Charles Mumbere, who hoped to establish an independent or at least autonomous kingdom in the Rwenzori Mountains.

[34] A few days later, Museveni ordered one of the FRONASA colums under Pipino to destroy the Akayanja bridge to sow unrest among a group of UA soldiers who camped at Rubiindi.

[21] In contrast, Avirgan and Honey claimed that the FRONASA guerrillas failed to destroy the bridge, having been scared off by the presence of Uganda Army soldiers.

[25] After the Moshi Conference during which the various anti-Amin rebel groups were unified as the Uganda National Liberation Front (UNLF), the TPDF troops finished their reorganization efforts at Mbarara and restarted their offensive.

[18] The Task Force began to advanced deeper into western Uganda, encountering Ugandan troops conducting rearguard defensive actions.

By night, most of those present had gotten drunk, and Brigadier Kitete held an emotional speech about forgiveness, referencing that Kilembe Mines employees had blown up Tanzania's Kyaka Bridge during the Kagera invasion.

Many Uganda Army soldiers exploited this to first flee across the border, and then launch raids from their new bases in Zaire into Tanzanian-occupied Ugandan territory.

[44] As the Tanzanians secured the border and Uganda Army troops fled the region, the separatist Rwenzururu movement exploited the unrest.

[32] After securing Kasese, the Task Force's main contingent continued its march toward Fort Portal; this part of the journey was highly taxing for the Tanzanian soldiers due to the terrain.

In the western theatre, Artillery & Signals Regiment commander Abdu Kisuule claimed that he ordered all UA troops in the Bunyoro region to rally at Masindi, but instead "they all ran for their dear lives".

The two units were initially unaware about each other's presence, and Task Force prepared to shell Hoima before being warned about the potential for a friendly fire incident over radio.

Believing that he had to delay the Tanzanian advance to ensure a more orderly retreat of the Uganda Army troops, Rwehururu rallied the Suicide Battalion and set up an ambush on the Masindi-Hoima Road.

When the combined contingents of the Task Force and 205th Brigade proceeded to advance toward Masindi,[50] Kisuule –by then acting as a TPDF guide– cautioned that the area ahead was well suited to an ambush.

[26] After Masindi, the Task Force and 20th Brigade had different targets; the former was supposed to secure the West Nile District to the northwest, while the latter was headed for Gulu.

[50] After a two-day delay due to fuel shortages, the 205th Brigade advanced to Karuma Falls, capturing the crossing after a short battle with a company of UA soldiers[51] on 17 May.

[54] Combat operations in Uganda continued until 3 June, when Tanzanian forces reached the Sudanese border and eliminated the last resistance.