Centre has issued high security alerts in view of possible threats following the killing of Al-Qaeda Chief Osama Bin Laden by US forces in Pakistan. The government has asked all the States to beef up security in and around the places having American or Jewish installations. The Home Ministry has asked authorities in Mumbai, Chennai, Hyderabad and Kolkata to enhance security around the US Consulates. The States have also been asked to keep vigil on tourist places frequented by foreigners.Security has also been enhanced in and around diplomatic enclaves in various cities. Meanwhile, the Border Security Force has been put on high alert in Punjab, Rajasthan and West Bengal to check any ingression and keep an eye on incidents happening around.