Police have arrested two would-be suicide bombers planning to attack a mosque and a government building in Pakistan's capital.
The arrests in Islamabad came as officials said another suspected US missile strike near the Afghan border killed three alleged insurgents.
Police spokesman Bin Yamin said the men detained in Islamabad were linked to the Pakistani Taliban in the South Waziristan region, where the army has been fighting the militants since last year.
One of the men was wearing an explosives vest and was on his way to attack an mosque during Friday prayers when officers seized him, Mr Yamin said. He did not say why the militants - who espouse a hardline interpretation of Islam - would target the mosque.
Al Qaida and Taliban militants seeking to topple Pakistan's US-allied government have carried out scores of attacks across the country, killing thousands. The military has responded by launching offensives in the remote north west where the insurgents are based, and the US has increased its barrage of missile attacks on those strongholds out of reach of the Pakistani army.
Most insurgent attacks have been on government, security or Western targets, though there have been seemingly indiscriminate blasts in public places presumably to spread terror and undermine confidence in the government. Questioning of the suspects indicated that the plotters were also planning to hit government buildings, possibly even parliament, Mr Yamin added.
Interior minister Rehman Malik said authorities learned about a possible suicide bombing at parliament or nearby buildings on Thursday night and quickly increased security in the area. "We took all the required measures without creating a panic," Mr Malik told the state-run Pakistan Television.
The last major terrorist attack in Pakistan's capital was in October last year, when a suicide bomber dressed as a security guard killed five UN staffers at the World Food Programme's office. The government has credited the relative lull to heightened intelligence gathering and increased police checkpoints around the city.
Also on Friday, suspected US missiles fired by an unmanned plane hit a vehicle carrying three alleged militants in a north-western Taliban stronghold, two intelligence officials said.
A pair of missiles hit the moving vehicle in Pir Kali village in North Waziristan, the officials said. The area is home to a mix of Afghan and Pakistani Taliban fighters who target American and Nato forces in Afghanistan.