Trucks laden with U.S. food and medicine returned to warehouses in Colombia after opposition supporters failed to break through lines of troops, who dispersed them with tear gas and rubber rounds, injuring dozens.

At least 40 people are believed to have been killed and some 850 detained amid anti-government protests in Venezuela over the past week, according to the United Nations human rights office. 

Thousands of Venezuelans took part in marches across the country to protest the government's decision to bar Capriles from running for office for 15 years.