**Funerals are being held amid tight security for a Sunni Muslim cleric and four others killed in two attacks in the southern Pakistani city of Karachi.**Mufti Saeed Ahmad Jalalpuri, head of a hardline Sunni organisation, was killed with three others by unidentified gunmen on Thursday.
Separately, gunmen targeted the leader of a banned Sunni Muslim group, injuring him but killing his son.
Police are blaming the attacks on sectarian tensions in the city.
Correspondents say the killings may be revenge for a spate of attacks against Shia Muslims over the last few months.
Tensions between the Shia minority and Sunni majority have been rising in Karachi in recent months.
Sectarian strife
Mufti Saeed Ahmad Jalalpuri was at the helm of a hardline religious group called the Interanational Organisation for the Defence of the Finality of Prophethood. The group challenged basic precepts of the Shia Muslim faith.
The other attack was on Maulana Abdul Ghafoor Haideri, a senior leader of the banned group Sipah-e-Sahaba Pakistan (SSP).
Maulana Haideri, two of his sons and a bodyguard were injured in the attack - but another son was killed.
Correspondents say the SSP is a militant group believed to be behind hundreds of gun and bomb attacks against Shia Muslims over the last three decades.