Complex sentence: At first, it was mainly used for connecting Dhaka and Chittagong, but in the mid- 1990s Biman started international flights to Dubai and a few Saudi Arabian cities and the airport officially became an international airport.
Split into simpler sentences: At first, it was mainly used for connecting Dhaka and Chittagong. But in the mid- 1990s Biman started international flights to Dubai and a few Saudi Arabian cities and it officially became an international airport.