Dozens dead after gunmen open fire on bus in Karachi

The attack occurred in the Safoora Chowk area of Pakistan's largest city 

Unidentified gunmen have opened fire on a bus in the port city of Karachi, killing at least 41 people and wounding many more, hospital sources have told Al Jazeera.

The attack occurred in the Safoora Chowk area of Pakistan's largest city on Wednesday.

Sixteen women were among the dead. A further 20 people are critically injured.

Those wounded are being treated at the Memon Medical Institute and Hospital. "Their condition is serious and they were covered in blood when they came in," said a hospital official.

The bus belonged to the al-Azhar Trust, a welfare arm of the Ismaili Muslim sect.

More information as it becomes available