A growing number of recruits from Western nations — including the U.S. — are traveling to Afghanistan and Pakistan to attend training camps run by al-Qaida and other terrorist groups, American and European counterterrorism officials say.

The flow of Western recruits has continued despite the intensified American campaign to take out terrorist leaders with drone missile attacks.

According to the Washington Post, A propaganda videotape released in September by a group calling itself the German Taliban showed a gunman identified as Abu Ibrahim the American. The tape was one of several released by groups affiliated with the Taliban and al-Qaida warning of an attack on German targets if the government did not withdraw its 3,800 troops from Afghanistan. At least 30 recruits from Germany have traveled to Pakistan this year for training, Germany security forces say.

The Post added:

“About 10 people — not necessarily the same individuals — have returned to Germany this year, fueling concerns that fresh plots are in the works against European targets.”

Pakistani officials in August arrested a dozen foreigners on their way to North Waziristan, a tribal region where many of the training camps are located. Among them was Mehdi Ghezali, a former inmate at the U.S. military prison at Guantanamo Bay.

In July, American officials announced that they had taken into custody New Yorker Bryant Neal Vinas, who confessed to traveling to al-Qaida camps in Pakistan and training to become a suicide bomber.

While he has been in custody, the U.S. has made a series of successful drone strikes on suspected al-Qaida locations in the Afghanistan-Pakistan border region, raising questions about whether Vinas provided the information that led to any of the deadly attacks, according to The Associated Press.

Vinas also told American authorities that he spent time in Pakistan with another New York resident, whose whereabouts are unknown. Al-Qaida and its affiliates have now developed an extensive recruiting network, The Post disclosed, with agents providing Western recruits with guidance, money, and travel routes to South Asia.