Troops loyal to President Nicolas Maduro violently drove back foreign aid convoys from Venezuela's border on Saturday, killing two protesters and prompting opposition leader Juan Guaido to propose that Washington consider "all options" to oust him.
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. Witnesses said masked men in civilian clothes also shot at protesters with live bullets.
"Today's events force me to make a decision: to formally propose to the international community that we must have all options open to secure the freedom of our country," Guaido said on Twitter.
The United States has been the top foreign backer of Guaido, who invoked Venezuela's constitution to assume an interim presidency last month and is now recognized by most Western nations as the OPEC nation's legitimate leader.
President Donald Trump has in the past said military intervention in Venezuela was "an option", though Guaido made no reference to it on Saturday. Guaido had given a personal send-off to one convoy carrying aid from the Colombian city of Cucuta on Saturday.
The opposition had hoped Venezuelan soldiers would baulk at turning back supplies desperately needed in the country, where a growing number of its 30 million people suffer from malnutrition and treatable diseases.
But while some 60 members of the security forces defected on Saturday, according to Colombian authorities, the lines of National Guard soldiers at the frontier crossings held firm, firing tear gas at the convoys.
At the Urena border point, two aid trucks caught fire, sending plumes of dark smoke into the air as crowds raced to try to save the boxes of supplies, a Reuters witness said.
Guaido said he would keep demanding Maduro let the aid in and would seek other routes. He said he would attend a meeting of the regional Lima Group of nations in Bogota on Monday with U.S. Vice President Mike Pence during which they would decide more actions to ramp up pressure on Maduro.
"Today the world saw in minutes, in hours, the worst face of the Venezuelan dictatorship," Guaido said at an earlier news conference in Colombia, alongside Colombian President Ivan Duque.
Angered by Duque's support for Guaido, Maduro said he was breaking diplomatic relations with Bogota and gave its diplomatic staff 24 hours to leave the country.
Maduro denies his oil-rich nation has any need of aid and accuses Guaido of being a coup-mongering puppet for U.S. President Donald Trump. Washington has warned it could seek to impose tough new sanctions on Venezuela at Monday's summit if Maduro blocked the aid shipments.