2 powerful back-to-back earthquakes rock Venezuela, damage and injuries reported

 Two powerful earthquakes -- a 7.2 magnitude quake followed just seconds later by a 7.5 -- rocked the coast of Venezuela on Wednesday evening, knocking down buildings in the capital and sending residents racing into the street.

In an address the nation Wednesday night, Venezeula's acting President Delcy Rodriguez said there was severe damage in the capital Caracas and other areas in the aftermath of the quakes.

She said Metro and rail services are suspended in the city and the Maiquetía International Airport, which was earlier reported to have sustained damage, is closed.

Photos and videos from Caracas showed some crumbled buildings, rescue crews searching through rubble and people being cared for on the street.

Crews responded to collapsed buildings in the areas of Alta Mira and Palos Grandes, according to authorities.

The U.S was preparing to send search-and-rescue teams, according to the State Department.

In a post on social media, Deputy Secretary of State Chris Landau said the U.S. was "mobilizing assistance" for Venezuela. 

Jeremy Lewin, the State Department's under secretary for foreign asssistance, said the department has "mobilized a disaster assistance team and task force to deliver and coordinate critical assistance to the Venezuelan people."

He added: "Working with our partners in the interim Venezuelan government, the U.S. will be sending search and rescue teams, medical and humanitarian supplies and other resources in the crucial first days after this tragic natural disaster."

Another State Department official confirmed that all staff at the U.S. embassy in Caracas are accounted for. 

The first earthquake -- a magnitude 7.2 -- was what the U.S. Geological Survey calls a "foreshock," recorded near San Felipe, Venezuela. Just 39 seconds later, a more powerful 7.5 "mainshock" was recorded in Yumare, according to the USGS.Past red alerts have required a national or international response, according to the USGS.

Following the quake, a tsunami advisory was issued, with the potential for hazardous tsunami waves possible for coasts within 300 kilometers of the earthquake epicenter. However, the tsunami advisory later expired.

ABC News' Will Gretsky, Shannon Kingston and Aicha El Hammar Castano contributed to this report.