Federica Mogherini said the EU rejected “any form of violence” and expects that a “comprehensive and transparent investigation” will be conducted to establish the fact of Saturday’s drone attack “in full respect for the rule of law and for human rights”.
Ms Mogherini added: “The EU expects the recognition of the National Assembly’s constitutional powers, including the full respect of its prerogatives concerning the parliamentary immunity of its members, in line with established constitutional rights, legislation and procedures.”
President Maduro claimed he was targeted by two explosives-laden drones during a rally in Caracas on Saturday, and has accused the opposition and the Columbian government of orchestrating the attack.
Earlier this week, Mr Maduro ordered the arrest of two lawmakers, exiled opposition leader Julio Borges and Juan Requesens.
He also named Columbia’s former leader, Nobel Peace Prize winner Juan Manuel Santos, as one of the plotters in a televised address.
Both Mr Borges and Mr Requesens have since been stripped of their parliamentary immunity.
But some members of the opposition, including Mr Borges, say the attack was staged by the Maduro regime in order to legitimise a brutal crackdown on the opposition.
Mrs Mogherini added: “The EU reiterates its support for a negotiated, democratic and peaceful solution for the multiple crises affecting the country as the only way forward.
“This must encompass a return to constitutional normality, the reestablishment of the democratic process and the rule of law, respect for fundamental rights and freedoms, the release of all political prisoners and addressing the urgent humanitarian needs of the population.”
Mr Maduro was re-elected for a second term in May in a win denounced both at home and abroad as a farce cementing autocracy following widespread allegations of vote buying and electoral fraud.
US President Donald Trump issued an executive order restricting Venezuela’s ability to liquidate state assets and debt in the United States, while Canada refused to recognise the results.
Venezuela’s unprecedented economic meltdown caused its economy to shrivel by 13 percent last year and has forced more than one million people to flee abroad.