Petróleos de Venezuela (PDVSA), Venezuela's state-owned oil company, was hit by a cyberattack over the weekend that disrupted its export operations.

In a Monday statement, PDVSA denied that the Saturday morning incident affected its operations in any way, adding that the breach was limited to some administrative systems.

"Thanks to PDVSA's human talent expertise, the operational areas were not affected at all, being reduced to an attack on their administrative system," the company said.

"Therefore, the operational continuity of the industry is maintained by the deployment of safe protocols that enable its regular activities in the supply of products to the national market, as well as for the fulfillment of all its export commitments."

However, according to an internal memo seen by Bloomberg, PDVSA instructed operational and administrative staff to disconnect from the network and shut down their computers.

Three sources familiar with the situation also told Bloomberg that systems on PDVSA's network that manage the country's main crude terminal were still offline on Monday.

This was confirmed by Reuters in a report citing an inside source who said, "There's no delivery (of cargoes), all systems are down."

​This cyberattack comes amid escalating tensions between Venezuela and the United States. Last week, U.S. authorities seized a sanctioned oil tanker with Venezuelan crude, the first such seizure since the U.S. Department of the Treasury's Office of Foreign Assets Control (OFAC) sanctioned PDVSA in January 2019.

In its Monday statement, PDVSA also blamed the United States and domestic conspirators for orchestrating the attack as part of an attempt "to undermine national stability."

"This attempted aggression is part of the US government's public strategy to seize Venezuelan oil by force and piracy," the company said.

"Petróleos de Venezuela, S.A. categorically rejects this despicable action, orchestrated by foreign interests in collusion with unpatriotic elements seeking to undermine the country's right to sovereign energy development."

Venezuela is one of the world's major oil-producing countries and a top global oil exporter. PDVSA oversees the country's oil production, refining, and exports, as well as the exploration and production of natural gas.