KABUL — Afghanistan's Defense Ministry on Wednesday said it has detained or removed hundreds of soldiers from its military's ranks as part of an investigation into the backgrounds of its troops after a surge in insider attacks against foreign forces. Defense Ministry spokesman Mohammad Zahir Azimi did not provide any other details or an exact numbers. He said many of the soldiers affected had been pushed out because they had either incomplete or forged documents. He did not say whether any were connected to the Taliban or other insurgent groups. Azimi added that the investigation began about six months ago but could provide no further details. He said more information would be released next week. On Sunday, the deputy commander of the US-led NATO coalition, British Lt. Gen. Adrian Bradshaw, also confirmed that a number of soldiers were suspended but also did not provide a number. The United States and its allies are pushing to have Afghan forces take over security for the country by the end of 2014. That effort has been imperiled by the spike in insider attacks, which have killed 45 international service members this year, most of them Americans. There were at least 12 such attacks in August alone, resulting in 15 deaths. The killings are straining an alliance already stretched by a tense relationship with Afghanistan's mercurial president, Hamid Karzai, and disagreements over NATO tactics that Kabul says endanger civilians. NATO Secretary-General Anders Fogh Rasmussen expressed deep concern to Karzai on Wednesday over the growing number of assaults by Afghan troops on coalition forces. Spokeswoman Carmen Romero said Karzai had assured Fogh Rasmussen in a phone conversation that he was doing all he could to stop the attacks. US Gen. John R. Allen, who commands NATO's 129,000-strong force, briefed the alliance's top decision-making body on Wednesday about the shootings. Coalition authorities have said about 25 percent of this year's insider attacks had confirmed or suspected links to the Taliban. The militants have sometimes infiltrated the ranks of the Afghan army and police and in other cases are believed to have coerced or otherwise persuaded legitimate members to turn on their coalition partners. The insider killings, the relentless violence around Afghanistan and the number of foreign troops dying — 318 so far this year — seem to run against NATO's narrative that its strategy in the country has so far been a success and that its plan to hand over security to local forces is on track. NATO did not comment on Azimi's remarks. Afghanistan inks deal with Iran for access to seaport The Afghan government has signed an agreement with Iran that gives land-locked Afghanistan access to a key seaport in the neighboring country. Afghan Foreign Minister Zalmai Rasool and Iranian Foreign Minister Ali Akbar Salehi inked the deal in Kabul on Wednesday. Rasool told reporters that the agreement guarantees Afghanistan access to the Iranian port of Chabahar on the Indian Ocean. Iran has been working to develop Chabahar as a regional economic hub.— AP