ISLAMABAD/KARACHI: Prime Minister Nawaz Sharif announced to observe a day of mourning across the country on Thursday following a deadly attack on Karachi's Ismaili community on Wednesday in which 43 people lost their lives.

Public offices will be flying flags at half-mast and a special prayers will be said for those killed in the attack.

Earlier, the Sindh government had also called for observing a day of mourning following the gruesome attack.

MQM and Tahafuz-e-Azadari Council also called for a day of mourning.

MQM Chief Altaf Hussain requested all businesses, educational institutions and public transportation be suspended in Karachi on Thursday.

At least 43 people were killed and 13 others wounded on Wednesday when armed men opened fire inside a bus carrying members of the Ismaili community near Safoora Chowk in Karachi.

Sindh Police Inspector General Ghulam Haider Jamali said that 60 people were on board the bus when six gunmen entered and executed 43 passengers.

Read more: 43 killed as gunmen attack bus carrying Ismaili passengers in Karachi