Zimbabwe's veteran leader Robert Mugabe has been sworn in for a new five-year term in a massive stadium inauguration that was boycotted by his election rival.

Mugabe, 89, pledged "to observe, uphold and defend the constitution of Zimbabwe" in an oath administered by Chief Justice Godfrey Chidyausiku, extending his 33-year rule.

Al Jazeera's Haru Mutasa reports from Harare.