Pakistan's interior minister on Saturday revealed that police foiled a plot to attack parliament during a presidential address and said a finance ministry official had been arrested.
"I commend the Islamabad police, they have foiled a plot to attack the parliament during president's address to the joint session," Rehman Malik told reporters.
"Police has arrested a suspect and an official of the finance ministry involved in the plot."
President Asif Ali Zardari addressed the joint sitting of the federal parliament on March 17 amid tight security.
Islamabad's government district is home to Western embassies, parliament, the presidency and the ISI intelligence headquarters and has seen several bombings and suicide attacks.
In October last year, police unearthed a major plot and seized a large quantity of arms and ammunition in a raid on a house in a suburb of the capital.
Islamist militants have killed more than 4,900 people across Pakistan since government troops raided an extremist mosque in Islamabad in July 2007.