Amid this activity, in November and December 1999, Mohamed Atta, Marwan al-Shehhi, Ziad Jarrah and Nawaf al-Hazmi visited Afghanistan, where they were selected for the "planes operation" that was to become known as &lt;a href="9/11"&gt;9/11&lt;/a&gt;. Al-Hazmi undertook guerrilla training at al-Qaeda's Mes Aynak camp (along with two Yemenis who were unable to get US entry visas). The camp was located in an abandoned Russian copper mine near Kabul, and was for a time in 1999 the only such training camp in operation. Atta, al-Shehhi and Jarrah met Muhammad Atef and bin Laden in Kandahar, and were instructed to go back to Germany to undertake pilot training.