Opposition leaders have long been calling on Venezuela's security forces to stop obeying Maduro.
However, there was also some speculation among opposition supporters on social media that the attack could have been staged to justify repression or cover up drama at Venezuela's National Assembly, where two dozen lawmakers said they were being besieged by pro-government gangs.
Earlier on Tuesday, Maduro warned that he and supporters would take up arms if his socialist government was violently overthrown by opponents.
"If Venezuela was plunged into chaos and violence and the Bolivarian Revolution destroyed, we would go to combat. We would never give up, and what couldn't be done with votes, we would do with arms, we would liberate the fatherland with arms," he said.
Maduro, who replaced Hugo Chavez in 2013, is pushing a July 30 vote for a special super-body called a Constituent Assembly, which could rewrite the national charter and supersede other institutions such as the opposition-controlled congress.
He has touted the assembly as the only way to bring peace to Venezuela. But opponents, who want to bring forward the next presidential election scheduled for late 2018, say it is a sham poll designed purely to keep the socialists in power.
They are boycotting the vote, and protesting daily on the streets to try and have it stopped.
Maduro said the "destruction" of Venezuela would lead to a huge refugee wave dwarfing the Mediterranean migrant crisis.
"Listen, President Donald Trump," he said earlier on Tuesday. "You would have to build 20 walls in the sea, a wall from Mississippi to Florida, from Florida to New York, it would be crazy ... You have the responsibility: stop the madness of the violent Venezuelan right wing."
Opposition to the July 30 vote has come not just from Venezuelan opposition parties but also from the chief state prosecutor Luisa Ortega and one-time government heavyweights such as former intelligence service boss Miguel Rodriguez.
Rodriguez criticized Maduro for not holding a referendum before the Constituent Assembly election, as his predecessor Chavez had done in 1999.
"This is a country without government, this is chaos," he told a news conference on Tuesday. "The people are left out ... They (the government) are seeking solutions outside the constitution." The government said pilot Perez was linked to Rodriguez. Neither men, nor representatives for them, could be reached immediately to comment on the accusations.
