The Sindh government in Pakistan has banned the entry of cricketer-turned politician Imran Khan after a bitter row with the ruling ally MQM over his threats to prosecute its London-based chief Altaf Hussain, prompting police at the Lahore airport to prevent him from boarding a flight to the southern port city on Sunday.

Reports from Lahore said Khan, who heads Tehrik-e-Insaf party, was stopped by police at the airport from going ahead with his programme to visit the headquarters of his ally the Jamat-i-Islami in Karachi.

Late on Saturday night the Sindh government banned the entry of Khan for a month after he alleged that self-exiled Hussain was responsible for the May 12 violence in Karachi during the visit of suspended Supreme Court Chief Justice Iftikar M Chaudhry in which 42 people were killed.

Khan said he would go to London on June 2 and assemble a team of lawyers to file a case against Hussain for his
alleged role in 'instigating' the violence.

The former cricketer termed Hussain as a 'fascist leader heading an authoritarian party'.

The ban on Khan's entry into Karachi came after MQM, which is part of the ruling coalition in Sindh, threatened to
hold demonstrations against him whenever he visited the city and wherever he went.

MQM activists held a major demonstration in Karachi on Friday shouting slogans against him and alleging that he was a
'womaniser' and 'playboy'. 

The party, which broadly represents the migrants from India known as 'Urdu speaking people' who were settled in
Karachi after independence, charged Khan with running a slander campaign against Hussain on behalf of his ally
Jamat-i-Islami.

MQM Parliamentarian Hyder Abbas Rizvi earlier told the media that unless Khan stopped his 'slander campaign' against the party and apologised he would face demonstrations whenever he visited Karachi and against whosoever invited him.

Khan hit back saying that MQM would he held responsible if he was attacked.