Doctors in Pakistan say contaminated medicines are believed to have killed at least 70 heart patients in the eastern city of Lahore. A hundred others are being monitored in hospitals. Some are said to be in a critical condition. Aura Garron reports from Islamabad.

The deaths are believed to be linked to a suspect batch of drugs given out in mid-December. A government official has told the BBC that 28,000 patients received the drugs. He denied the medications have no expiry dates. As other officials have claimed, several arrests have been made and at least one pharmaceutical firm has been closed. But relatives of the dead have accused the authorities of responding too late. Hospital sources have told the BBC they are under pressure to buy the cheapest drugs available.

The Senegalese musician, Youssou N'Dour, has registered to stand for the country’s presidential elections to be held on the 26th, February. He announced his plans to run earlier this month.

World News from the BBC.

The Nigerian president Goodluck Jonathan has sacked the country’s police chief after a spate of attacks by the Islamist group, Boko Haram. And the attack by Boko Haram in the northern city of Kano last Friday left 185 people dead and the group is suspected of striking again on Tuesday night. From Lagas, Mark Lobel reports.

The earlier retirement of Hafiz Ringim, Nigeria’s most senior police officer just weeks before his official leaving date, illustrates the urgent pressure on the authorities to restore public faith in the force after the recent deadly attacks by the militants across the country. A fatal blow to Mr.Ringim’s reputation as someone unable to deal with the Boko Haram insurgency, came with the escape after 24 hours in custody of the suspected mastermind’s bombings which killed at 38 people in the church on Christmas day.