Thousands of demonstrators took to Caracas' streets on Saturday to press for the release of imprisoned foes of President Nicolas Maduro's government.

Summoned by jailed opposition leader Leopoldo Lopez, about 3,000 supporters jammed a main thoroughfare in Caracas to rally alongside his wife, Lilian Tintori, and the wives of former San Cristobal, Tachira mayor Daniel Ceballos, and Caracas mayor Antonio Ledezma -- all fellow Maduro opponents behind bars.

Venezuela's public ombudsman denied Monday that jailed opposition leader Leopoldo Lopez was on hunger strike or in solitary confinement, saying he "had lunch with his children" the day before.

Lopez said Saturday he was launching a hunger strike with fellow inmate Daniel Ceballos, a former student leader and ex-mayor, to protest the political situation in the country.

Jailed Venezuelan opposition leader Leopoldo Lopez and another high-profile detainee began a hunger strike Saturday to protest political repression in the South American nation.

Lopez announced the action in a four-minute video that was surreptitiously filmed in his narrow prison cell and released on YouTube.

U.S. prosecutors are investigating several senior Venezuelan officials over alleged involvement in large-scale cocaine trafficking, The Wall Street Journal reported on Monday, citing more than a dozen people with knowledge of the case.

The Journal report said Drug Enforcement Administration investigators and federal prosecutors in New York and Miami were building cases based on evidence supplied by former cocaine traffickers, informants with close ties to Venezuelan officials and defectors from the Venezuelan military.

Despite the bloody conflicts raging in the Middle East, Central America remains the region with the highest number of violent deaths worldwide, a U.N. report showed Friday.

The Global Burden of Armed Violence report, published every four or five years, charts violent fatalities linked to conflict and other reasons across the world.

With a brand new Americas office in Mexico City, Amnesty International wants to tackle the "hidden crisis" afflicting human rights in the vast region, the organization's head said Tuesday.

In an interview with Agence France Presse, secretary general Salil Shetty said the first headquarters based inside the region, covering from North to South America and the Caribbean, will allow the rights groups to react faster to a slew of problems.

Venezuela's President Nicolas Maduro joined President Raul Castro at a huge May Day rally in Havana on Friday in a show of socialist unity minus the usual anti-imperialist rhetoric.

Amid a tropical rain shower, Castro saluted thousands of people as they passed the reviewing stand at the Plaza of the Revolution in the Cuban capital.

President Nicolas Maduro said Tuesday he will announce economic reform measures this week, as Venezuela grapples with severe inflation, shortages and other woes.

The heir to the late leftist firebrand Hugo Chavez said he wanted to "win the economic war along the path of socialism".

Spain recalled its ambassador to Caracas Wednesday after Venezuelan President Nicolas Maduro accused Madrid of "terrorism", as a row between the two countries intensified.

"Given the level of verbal irritation that I have seen from president Maduro, I have decided to recall our ambassador to Caracas for consultation," said Foreign Minister Jose Manuel Garcia-Margallo.

The United States is interested in improving its ties with Venezuela, a relationship that has been "severely strained" in recent years, Secretary of State John Kerry said Tuesday.

"The U.S. remains open to further addressing our differences in attempting to find areas of common ground," Kerry said during a speech at the State Department.