KARACHI: With tears and overwhelming grief, friends and loved ones on Thursday performed the final rites of the 43 ill-fated men and women who were gunned down mercilessly in Karachi's Safoora Goth area a day earlier.

A large number of citizens and representatives of political parties also attended the funeral prayers.

Funeral prayers of 43 victims of the massacre were offered in Safoora Goth's Al-Azhar Garden area of the provincial capital city while their burial took at the Sakhi Hasan graveyard.

Two more injured passengers belonging to the Ismaili community succumbed to their wounds on Thursday taking the death toll to a grisly 45.

A national day mourning is being observed to express solidarity with the targeted Ismaili community over the massacre that shocked the nation.

National flags at all government and semi-government buildings are flying at half mast.

Mourning is also being observed in Azad Jammu and Kashmir.

Read: 43 killed in attack on bus carrying Ismailis in Karachi

Six gunmen stopped the bus, which was carrying members of the Ismaili community, near Safoora Chowk and first fired at it from outside, according to a police official. Then the assailants entered inside the bus and open fire indiscriminately.

The bus was carrying more than 50 people at the time of the attack.

The attack was claimed by a division of the self-styled Islamic State (IS) militant organisation.

Condemnations poured in from across the country while Chief of Army Staff General Raheel Sharif cancelled his visit to Sri Lanka and departed for Karachi after the attack. He also called Prince Karim Agha Khan and offered his condolences.

Prime Minister Nawaz Sharif, Pakistan Peoples Party (PPP) Chairman Bilawal Bhutto Zardari, Pakistan Tehreek-i-Insaf (PTI) Chairman Imran Khan, Muttahida Qaumi Movement (MQM) Chief Altaf Hussain and leaders of almost all political parties in the country strongly condemned the incident.

The attack also prompted the prime minister and army chief to cancel engagements and rush to Karachi, where an hours long meeting was held to discuss a course of action to apprehend the perpetrators.

Read: Attack on Ismaili community

The Ismailis in Pakistan are a peaceful, progressive and largely apolitical community predominantly working in the health and education sectors.

In the past there has been anti-Ismaili violence in Chitral and Gilgit-Baltistan, mostly in the form of communal flare-ups.

In 2013, a bomb attack at Karachi's Aisha Manzil killed four and injured 42 others. The outlawed Tehreek-i-Taliban Pakistan had claimed responsibility for the earlier attacks.