Bulgarian Defence Minister Anyo Angelov and General Simeon Simeonov will participate in the official send-off ceremony in Karlovo, central Bulgaria, on June 24 2010 for a company-sized military detachment heading to Afghanistan.The soldiers will join the International Security Assistance Force in order to bolster security at Kandahar Airport, the private Bulgarian television channel bTV said.Bulgaria has also announced it plans to send 65 more soldiers to the Nato-led force in Afghanistan in early September. According to a government statement, 10 of the contingent will be medical service personnel based in Kabul and Kandahar, and 10 will be instructors for the Afghan army.The rest will join a Bulgarian unit guarding the airport in Kandahar. Bulgaria currently has 527 troops in Afghanistan, 310 of them guarding the airport.The decision to send more troops comes a week after a letter from US president, Barack Obama to Bulgarian Prime Minister, Boyko Borissov, hailed Bulgaria's help in the missions in Afghanistan.The letter, dated April 20, was only made known to the public on June 17. In the letter, Obama expressed his gratitude for Bulgaria's support for military operations in Afghanistan, and the country's stance on Iran, the NATO-proposed missile defence shield and for the country's policies on energy security matters."I would like to express my deepest gratitude for your efforts in Afghanistan and for the courage and the determination of Bulgarian soldiers," Obama said.