Malik said an employee of the Foreign Ministry was involved in the conspiracy but did not give any other details.
The terrorists had planned to attack Parliament when President Zardari was delivering his address on March 17, he told reporters here.
However, he did not name any militant group. Authorities had put in place extensive security arrangements for the joint session of Parliament addressed by Zardari on March 17.
Hundreds of security personnel were deployed in the “Red Zone” at the heart of Islamabad, where Parliament is located, and helicopters were used to carry out aerial surveillance of the city.
In recent months, Pakistani police said they had foiled another plot by terrorists to target key buildings like Parliament and the Presidency.
According to media reports, the terrorists had plans to fire rockets at the buildings from mountains overlooking Islamabad, following which suicide attackers would storm the structures.