A court in Burundi has sentenced 21 opposition supporters to life in prison for participating in an illegal demonstration that turned violent.
Another 26 Movement for Solidarity and Democracy (MSD) supporters were given shorter jail terms.
They denied participating in a march and say they were out jogging when a police crackdown began.
Meanwhile, a government attempt to change the constitution has failed to gain enough parliamentary support.
Opposition parties boycotted the session as they felt the amendments would have undermined reconciliation agreements that ended the country’s long ethnic-based civil war in which some 300,000 people died.
The government wanted to create a post of prime minister and reduce the role of the senate in overseeing the ethnic balance in state institutions but it fell one vote short of the required 80% majority.
The BBC’s Prime Ndikumagenge in the capital, Bujumbura, says the government’s proposals have been partly to blame for the recent rise in political tensions in the small East African nation.
In Burundi, permission must be sought from the authorities to hold a political march or public gathering.
Police say that on Saturday 8 March, they had intelligence that sporting activities were going to be used as a front to organise illegal demonstrations.
Officers were deployed in the city to prevent this happening.
But the situation deteriorated into clashes and some of the joggers tried to seek refuge in the MSD headquarters, taking two policemen hostage.
Several people were injured in the fracas and afterwards about 70 MSD supporters were arrested, with 48 facing life sentences for insurrection.
The authorities have since restricted jogging clubs to certain areas.
All sports must now take place in nine parks in Bujumbura and other designated football pitches, it was announced earlier this week.
Our correspondent says jogging is a national pastime, with hundreds of people out running or taking a walk on weekend mornings.
MSD leader Alexis Sinduhije was also charged over the clashes, but has not been caught.
Those found guilty on Friday are to appeal against their sentences.
The court in Bujumbura also acquitted 22 of defendants.
Presidential elections in Burundi, one of the world’s poorest countries, are due next year – they will be the third since the official end to the conflict.
Under a series of peace deals, up to 40% of posts in various state institutions, including parliament, are reserved for members of the minority Tutsi community.
Laws currently need a two-thirds majority to be passed but the constitutional changes would have changed this to a simple majority, effectively removing the Tutsi blocking veto.