Nyerere did not initially intend on expanding the war beyond defending Tanzanian territory. After Amin failed to renounce his claims to Kagera and the Organisation of African Unity offered only limited criticism of the Ugandan invasion, he decided that Tanzanian forces should occupy southern Uganda. The Tanzanians constructed an air strip in Mutukula so transport aircraft could resupply the troops at the front lines. In February the TPDF was ordered to capture Masaka and Mbarara. Both towns were subsequently seized by Tanzanian and Ugandan rebel forces and destroyed with explosives. Shortly thereafter Ugandan MiG-21s attempted to bomb the Mutukula air strip, but were repulsed by anti-aircraft missiles. Nyerere originally planned to halt his forces in Masaka and Mbarara and allow the Ugandan rebels to attack Kampala and overthrow Amin, as he feared that scenes of Tanzanian troops occupying the city would reflect poorly on his country's image abroad. However, Ugandan rebel forces did not have the strength to defeat the Libyan units coming to Amin's aid, so Nyerere decided to use the TPDF to take Kampala. The city fell on 11 April. The TPDF withdrew from Uganda in 1981.