Updated

PESHAWAR, Pakistan (AP) — The path to terrorist training in Pakistan is well worn — developed and maintained by established militant groups that have operated for decades. They are open to those — Americans included — with enough determination and savvy to navigate both the extremist networks and the dangerous borderlands.

Faisal Shahzad, the Pakistani-American charged in the failed Times Square bombing, is among those to make the journey, U.S. prosecutors allege. Five young American Muslims tried to link up with extremists with less success, officials say: They now face trial in Pakistan.

Retired Brig. Mahmood Shah, the military's former pointman in the tribal regions, said the numbers of would-be jihadis are dropping because Pakistani military operations and two years of U.S. drone airstrikes have made Somalia and Yemen more attractive destinations.

But analysts and Pakistani officials say that for those would-be jihadists, including foreigners, willing to take the risk, it is surprisingly easy for them to reach training facilities in the border area.

Would-be jihadis, many of whom are recruited by al-Qaida operatives abroad, enter Pakistan, either through the northwest city of Peshawar or the southern port city of Karachi. From there they make their way through safe houses to the border area, according to Pakistani intelligence and security officials.

Training takes place in makeshift mobile camps that move about to avoid detection by U.S. drones that have killed up to 300 people this year, according to the New America Foundation, which keeps a database of the attacks. Human rights groups believe many of the dead have been civilians, fueling anti-Americanism among Pakistan's 175 million people and possibly encouraging young Muslims to join the jihad.

A Pakistani intelligence official involved in the investigation into Shahzad's activities in Pakistan said al-Qaida operatives arrange their trip to Pakistan and provide a local contact who takes them from the airport to the network of safe houses, usually in congested neighborhoods.

Once in the country, foreigners of Pakistani origin such as Shahzad can move freely, especially if they hold dual citizenship. Officials say they are not routinely shadowed by the intelligence service unless their names are on an international watch list.

Trainees travel to and from the camps with escorts, who often are strangers to one another, so if that if one is arrested, the rest of the network is not compromised, the official said on condition of anonymity because he's not supposed to release information.

The brother of a militant who had attended a camp in North Waziristan said training lasts about 20 days. Lectures on the philosophy of jihad are usually delivered by foreigners, mostly Arabs, he said, speaking on condition of anonymity for his own safety.

The network relies on numerous militant organizations — such as Sipah-e-Sahaba, Jaish-e-Mohammed and Lashkar-e-Janghvi — which have existed in Pakistan for decades.

For security and logistics, the network also relies on private religious schools, or madrasas, as well as mosques with links to extremist groups. Some foreign militants enter the country on visas to study at a madrasa. Others are helped by madrasa students or staff, who can provide places to stay and help with transport inside the country.

Former President Pervez Musharraf promised years ago to curb the madrasas and regulate their curricula to eliminate Islamic extremist teachings. Those efforts fell short due to the political power of the religious establishment in a country where madrasas are often the only source of education for the nation's poor.

In the capital of Islamabad alone, there are 305 madrasas with about 28,000 students, most of them from the tribal areas, according to a senior police official who spoke on condition of anonymity because he's not supposed to release information.

Between 10 and 15 of the schools are under police or intelligence surveillance with paid informants inside, he said. Those schools often attract young Muslims from the Middle East whose countries have clamped down on religious schools for fear they are training grounds for extremists.

"In many countries in the Middle East such as Turkey or Egypt or Jordan it is difficult to get access to a fundamentalist or militant madrasas," Brian Glyn Williams, a terrorism expert at the University of Massachusetts, said in an e-mail. "Those who want this sort of education travel to Pakistan through well-established networks."

The proliferation of militant groups — some banned but still operating under new names — featured prominently in recent talks in Islamabad between Pakistani officials and CIA director Leon Panetta and National Security Adviser James Jones, according to Pakistani officials close to the talks but who spoke on condition of anonymity because the discussions were private.

For years Pakistani officials tolerated such groups because they focused their operations in Indian-controlled areas of the disputed Kashmir region. The government launched a war against the Pakistani Taliban after they began attacks on targets inside Pakistan.

However, evidence is growing of cooperation among the groups, including the Taliban, blurring the lines between those who work against Pakistan's interest. Khalid Sheikh Mohammed, the alleged mastermind of the Sept. 11, 2001 terrorist attacks in the United States, was arrested in March 2003 in Karachi at the home of a member of Jamaat-e-Islami, a legal religious party.

"The government calls the jihadi rebels who fight the state 'splinters'...but their human resource pool is the same and so is their ideology," said Ayesha Siddiqa, an expert on militant groups in Pakistan and a visiting professor at Johns Hopkins University.

Jordanian doctor Humam Khalil al-Balawi, who carried out the Dec. 30 suicide attack against the CIA base at Camp Chapman in eastern Afghanistan, was recruited by al-Qaida but trained in Pakistan by the Qari Hussain, the explosives expert of the Pakistani Taliban. Hussain is also a member of Lashkar-e-Janghvi, a Sunni sectarian group.