Colombia farmers and police clash over government policies
23 August 2013 Last updated at 20:06 BST
Farmers and truck workers in Colombia have clashed with police over the government's agricultural and economic policies.
The protests - which started peacefully - took a violent turn on Thursday, the fourth day of action, when teargas was fired at protesters who threw rocks and set fire to vehicles in the city of Zipaquira.
Daniel Pardo reports.