Loud noises and low-flying aircraft were heard in the Venezuelan capital, Caracas, in the early hours of Saturday morning, according to witnesses cited by international agencies.
The southern area of the city, near a major military base, was without electricity.
US President Donald Trump for months had threatened that he could soon order strikes on targets on Venezuelan land.
Venezuelan President Nicolas Maduro said in a pre-taped interview aired Thursday that the US wants to force a government change in Venezuela and gain access to its vast oil reserves through its current military campaign.
Trump administration officials have called Maduro an "illegitimate leader" and a narco-trafficker.
Maduro has denied those accusations and kept a firm grip on power since declaring himself the winner of 2024 elections, which he lost, according to independent observers.
The US has built enormous military pressure on Venezuela since August, carrying out dozens of strikes on alleged drug-trafficking boats in international waters.
Trump last week appeared to reveal a clandestine US operation where US personnel struck a remote dock on the coast of Venezuela.
If the US strike is confirmed, it will mark the first known land strike on Venezuela since the US began a buildup of strike forces in the region.
Trump last year also announced a blockade on all sanctioned oil tankers coming in and out Venezuela and other financial tactics to increase pressure on Maduro.
