Bihar's well-known conjoined twins, Saba Shakeel and Farah Shakeel, are excited to cast their votes for the first time in their life on Wednesday. But there is a hitch. They can't vote separately.

The 18-year-old sisters, who are joined at their heads and share an artery that carries blood to their hearts, will have to agree on the candidate they want to vote for in the Digha constituency going to polls in this phase.

According to their family, the sisters have been issued a common voter identity card by the Election Commission of India which will not allow them to cast their votes separately. The card also has their names clubbed as "Saba Farah."

Saba said that she could not understand why her sister and she were considered one person when they are two different individuals.

Tamanna Mallick, Saba and Farah's elder brother, said that his sisters should have been issued separate voter identity cards. "They both are keen on taking part in the greatest festival of democracy and want to vote for development," he said.

Tamanna claimed that he had pointed out the discrepancy to the Election Commission officials but was told that his sisters could cast their votes separately if their names were separately entered on the electoral roll.

The family members also pointed out that there was another discrepancy in their card. "Their birthday has been entered as Januray 1, 1990 but in reality, they were born on March 1, 1997," Tamanna said.

Farah and Saba shot into the limelight in 2005 when leading American neurosurgeon Dr Benjamin Carson from Johns Hopkins Children's Centre in Baltimore, USA came down to examine them at a Delhi hospital and expressed hope to successfully separate them through surgery. But their parents did not agree because of the risks involved. In June 2011, the parents of the twin sisters had pleaded for their mercy killing after their health deteriorated.