They were detained after a shoot-out near a village in central Pakistan, said Abdi Qadri, a senior police officer, and revealed their plans under interrogation.
The men, suspected members of Lashkar-e-Jhangvi (LeJ), a banned Sunni militant group linked to the Taliban and al Qaeda, told police officers they were devising a plot to attack the home of Yousuf Raza Gilan, the prime minister, in Multan.
"We have averted several high-profile attacks by arresting these terrorists," said Mr Qadri.
The men opened fire when police tried to stop their car for a routine check.
Two passengers managed to escape on foot.
Mr Qadri added that some of the suspects were believed to have taken part in last year's attack on the main Pakistani spy agency in the central city of Multan that killed 12 people.
They also had plans to attack a key dam, a bridge and military installations as well as Shah Mahmood Qureshi, the foreign minister.Source.
The timing of this "plot" is really interesting, as it appears when there are some reasonable doubts about Pakistani involvement with the Talibans (here, here and here).