Iranian twins Ladan and Laleh Bijani were buried side by side, but in different graves on Saturday as thousands mourned the conjoined sisters whose determination to lead separate lives touched people around the world. Mourners lined the hillsides, in a valley in southern Iran, and beat their chests as a Muslim cleric read verses from the Qoran.Meanwhile, a doctor who was involved in the unsuccessful attempt to separate them today said he would not recommend a similar operation for others. ‘‘With the knowledge that has been gained, I would not do it the same way. With this information, I wouldn’t be enthusiastic about it and I would probably discourage people from it,’’ consulting neurosurgeon Benjamin Carson told BBC.From John Hopkins Children’s Center Carson flew to Singapore to assist doctors in their attempt. The historic operation which had never been attempted on adult conjoined twins, ended tragically when they died within 90 minutes of each other after a marathon operation on Tuesday.