Juan Guaidó was seized after he declared himself ready to assume the presidency in a bold challenge to its leader Nicolás Maduro

Venezuelan secret police seized and then swiftly released a prominent opposition leader, less than 48 hours after he declared himself ready to assume the presidency of his crisis-stricken country in a bold challenge to its leader Nicolás Maduro.

Juan Guaidó, the 35-year-old head of Venezuela’s opposition-run parliament, was reportedly taken by agents from the Bolivarian National Intelligence Service (Sebin) on Sunday morning as he travelled north out of the capital, Caracas.

Juan Guaidó said he has constitutional right to assume leadership because Maduro is an illegitimate ‘usurper’

The head of Venezuela’s opposition-run parliament has thrown down the gauntlet to his country’s embattled leader, Nicolás Maduro, declaring himself ready to assume the presidency, in a rare and potentially destabilizing challenge to two decades of Bolivarian rule.

Related: Maduro starts new Venezuela term by accusing US of imperialist 'world war'

President Nicolás Maduro shrugged off a tempest of international condemnation to begin his second term in office

The Venezuelan president, Nicolás Maduro, has castigated the European Union and accused Washington of waging an imperialist “world war” against his crisis-stricken nation, as he shrugged off a tempest of international condemnation to begin his second term in office.

Maduro, who inherited Hugo Chávez’s Bolivarian revolution after his 2013 death, has overseen a calamitous decline in his country’s fortunes and was re-elected in disputed elections last May.