Gunmen open fire in Pakistani Stock Exchange, all 4 terrorists shot dead; Delhi to have plasma bank, CM Kejriwal seeks volunteers, says no risk in plasma bank; Hardline separatist Syed Ali Shah Geelani resigns as chairman of Hurriyat Conference, cites some issues; Covid-19 death toll hits 500,000 worldwide, South Asia, Africa contributing cases too; BSP chief Mayawati backs Centre on china border issue and more news