The British government has expressed satisfaction over the enhanced security measures taken by the Bangladesh government at Hazrat Shahjalal International Airport.British Prime Minister David Cameron wrote back to her Bangladesh counterpart Sheikh Hasina a couple of days ago, saying the British government was happy with the improved security at Dhaka airport, a diplomatic source in Dhaka told The Daily Star yesterday.Another diplomatic source said Cameron wrote to Hasina on April 8 in response to her March 14 letter in which she requested a review of the ban on direct air cargo from Dhaka to London.Earlier on March 8, Cameron wrote to Hasina, seeking her initiatives to boost security at the airport.