Eight Brazilian senators who were trying to meet with jailed opposition leader Leopoldo Lopez in Venezuela say that they had to flee for safety after their bus was attacked.

The group claims their bus was pelted with stones as it drove away from the Caracas airport.

"Our bus was under siege; they were beating and trying to break it. I filmed them throwing stones against the bus," Sen. Ronaldo Caiado tweeted, according to the BBC.

Aecio Neves, a former presidential candidate, voiced his frustration as well, saying, "We are here to defend democracy and until now the Venezuelan government has shown little appreciation of it."

Leopoldo Lopez, the jailed 44-year-old opposition party leader, is accused of inciting violence during protests last year which, according to President Nicolás Maduro, resulted in over 50 deaths.

Lopez's wife, 37-year-old activist and former media personality Lilian Tintori, wrote an opinion piece for the Washington Post in which she said the government has vowed to keep her husband in prison for a decade.

Lopez is currently on a hunger strike.

Guillermo Seijas, a gastroenterologist and former minister of health, said López is at a stage in his hunger strike where complications might arise.

"If I were one of those doctors who work for the government or the jail, in accordance with the medical ethical code and the Declaration of Malta, I would have requested a private doctor to advance his assessment," Seijas said as reported by El Universal.

Brazil's foreign ministry said it will seek an explanation from the Venezuelan government regarding the alleged bus attack.

This is not the first time political figures from other nations have somehow been averted from seeing the jailed opposition leader.

Spanish Prime Minister Felipe Gonzalez left Caracas earlier this month after failing to speak to Lopez. The Venezuelan Congress had classified Gonzalez "persona non grata."

President Maduro has been vocal all along about his suspicion of all the foreign support coming to the Venezuelan opposition leader.