Senator Marco Rubio (R) has continued to advocate for Venezuelan opposition amid a deepening crisis, amplifying reports of protests and alleged human rights abuses, and posting aggressive tweets.

Rubio has been a longtime supporter of the Venezuelan opposition because of President Maduro's association with the Cuban government.

On Sunday, he tweeted about an alleged poisoning of an opposition lawmaker, and posted bloody photos of former dictator Muammar Gaddafi, seemingly a reference to Maduro.

Amid a deepening political and economic crisis in Venezuela, Florida Senator Marco Rubio (R) has gotten involved in bringing attention to the situation, implying Saturday evening that an opposition lawmaker in the country was politically poisoned, and posting bloody images of the former leader of Libya Muammar Gaddafi, seemingly as a sort of warning to Venezuela's embattled president Nicolás Maduro.

"Grave situation developing right now inside of #Colombia." Rubio tweeted. "[Freddy Superlano] a member of the National Assembly of #Venezuela was poisoned this morning at breakfast inside of Colombia & is in serious condition at the hospital. His assistant Carlos Salinas has died from poisoning."

According to BNO News, Voluntad Popular, the opposition party of Juan Guaidó, says that the Venezuelan lawmaker was poisoned in the city of Cúcuta near the Colombia-Venezuela border, along with his cousin who died.

BNO News reports that it's believed that the poison used was Burundanga, known as "devil's breath," a drug that is often used for motion sickness, but that has also reportedly been used in Latin America for robberies and sexual assaults. The drug has also been the subject of viral urban legends in the US.

Neither the party nor Rubio directly called the alleged poisoning a political attack. In a statement, the party said, "We wait for the results of the investigation by the Colombian authorities to establish the facts."

In another tweet, directly following one about the "#MaduroCrimeFamily," Rubio posted uncaptioned before and after picture of former Libyan leader Muammar Gaddafi, with the before showing a photo of him in power, and the after showing him beaten to a bloody pulp. The tweet, in the context of his series of recent tweets on Venezuela and Maduro, seems to be a veiled warning for Maduro, who is considered to be a leader that's overdue for recall.

A deepening crisis

Over the weekend, the border between Colombia and Venezuela has exploded in conflict.

Two died and 300 were injured Saturday near the border as troops loyal to President Nicolas Maduro, who believes the aid is part of a potential coup, clashed with demonstrators who were protesting the blockage of US aid coming through Colombia.

The shipments included much-needed food and medicine for the country that has been starved by economic crisis.

Read more: Photos show chaos in Venezuela as protesters and soldiers clash over humanitarian aid shipments

Protesters told the Associated Press that Maduro's troops set 2 aid shipments on fire, and fired tear gas at protesters.

After the protests, opposition leader Guaido, who much of the international community recognize as Venezuela's rightful leader, did not call for more protests

Marco Rubio's long battle with Maduro

U.S. Senator Marco Rubio, R-Fla., greets Venezuelan migrants near the Simon Bolivar International Bridge, which connects Colombia with Venezuela, in La Parada, near Cucuta, Colombia, Sunday, Feb. 17, 2019. As part of U.S. humanitarian aid to Venezuela, Rubio is visiting the area where the medical supplies, medicine and food aid is stored before it it expected to be taken across the border on Feb. 23. AP Photo/Fernando Vergara

Senator Rubio has been a longtime opponent of Maduro's, and has recently ramped up his statements against the Venezuelan leader.

In January, Rubio suggested that Maduro's ouster was a given, saying, "It’s just a matter of time. The only thing we don’t know is how long it will take — and whether it will be peaceful or bloody."

Rubio is said to have been key in President Trump's decision to back opposition leader Guaidó and send aid.

Rubio, a Cuban-American, stands with other Cuban-American leaders in his opposition to Maduro, who's variant of socialism has been associated with the Cuban government.

Last week, Rubio visited the Colombian-Venezuelan border, where he asked the Venezuelan military to let aid shipments through, and spoke alongside delegates of Guaido's team.

"Soon, Mr. President, we will be standing together in a free Venezuela," he said.

Vice President Mike Pence is scheduled to meet with Guaido on Monday.