Since January, missiles reportedly fired from CIA-operated Predator drones have hit at least three suspected hideouts of Islamic militants, including a strike last Sunday on a house in a South Waziristan village called Toog.

The surge began after visits to Pakistan at the beginning of the year by senior US officials, including intelligence czar Mike McConnell, CIA director Gen. Michael Hayden and Adm William Fallon, who recently resigned as commander of the US forces in the region.

Some news reports said at the time that Musharraf had "rebuffed" US proposals to step up combat operations inside Pakistan.

But US officials and Pakistani sources, who asked for anonymity discussing sensitive information, said the recent wave of Predator attacks are at least partly the result of understandings the high-level visitors reached with Musharraf and other top Pakistanis, giving the US virtually unrestricted authority to hit targets in the border areas.

One former official said that the United States has been relying on its own intel to uncover terror targets because Pakistani intelligence agencies are weak on espionage in the tribal areas.

By contrast, U.S. forces have a heavy presence on the Afghan side of the border. Bruce Riedel, a retired CIA expert on the region, said that a new wave of terrorism inside Pakistan -- there were 62 suicide attacks last year, after just six in 2006 -- has forced Musharraf and the new military chief, Gen. Ashfaq Kiyani, to acknowledge that the same extremists threatening Americans now also pose a growing threat to Pakistan's internal security.

Another reason for the rise in Predator strikes, according to a current U.S. official: Washington fears that any newly formed civilian government in Pakistan will be more hostile to U.S. operations there than Musharraf's current regime. Time to act, in other words, may be running out.

At least one top Al Qaeda operative has been killed in the Predator strikes.

After a missile hit a home in North Waziristan in late January, reportedly killing 10 militants, US officials confirmed that among the dead was Abu Laith al-Libi, a top field commander who was believed to be a liaison between Al Qaeda's fugitive leaders and Taliban fighters in Afghanistan.

Since then there have been reports that more attacks are being carried out.

The CIA declined to confirm or comment on any of the reported attacks, but three current and former US officials, who also asked for anonymity, said that the one-per-month strike rate is definitely higher than in previous years.