Some 21 candidates have filed their nomination papers with the Returning Officer for contesting by-election to provincial assembly seat PS- 57 (Badin). Barrister Hussnain Mirza, son of Dr Zulfikar Mirza has also filed nomination papers as candidate of Pakistan Peoples Party (PPP), among others. The by-election will be held on February 15 for the Sindh Assembly seat, fell vacant after the resignation of former provincial minister Dr Zulfikar Mirza.