LONDON (Agencies) - Security officials on Tuesday warned of further attacks planned by the Taliban in the Punjab, following an attack earlier in the day on the well-secured office of the Inter-Services Intelligence in of Multan. On Monday, Lahore was rocked by two bomb blasts in a crowded market that left at least 54 people dead. This came as the Supreme Court has begun hearing a legal challenge to an amnesty issued by former president Pervez Musharraf last year, which benefited senior politicians from the ruling PPP including those considered close to the President. The worsening security situation could not have come at a more inopportune moment for Pakistan, said one western diplomat. The emerging pattern suggests that the Punjab, which is Pakistans heartland, is now fast under threat, a senior Pakistani security official told the Financial Times on Tuesday. The Taliban are eager to retaliate to discourage the military from pressing ahead with an operation against them. The upsurge in militant attacks comes almost two months after Pakistan Army began a campaign in the South Waziristan region to wipe out sanctuaries believed to be used by Taliban in the area. In a related development, a former director-general of the ISI, who is widely known to be a strong nationalist, publicly called for a review of Pakistans relations with the US, notably Islamabads apparent tolerance of continued attacks by CIA-flown pilotless drone aircraft. In public, the Pakistani government has protested against those attacks, though in private senior officials have said they serve a useful purpose in targeting well-known militants. We have to take a tough position on this issue. The problem for Pakistan is that the drone attacks have only added to the popular anger in the border region [alongside the Afghan border], said Lt-Gen (retd) Hamid Gul. He said Pakistan should consider options including refusal to allow logistical supplies for US troops in Afghanistan that passed through Pakistan if the drone attacks did not end.