Security has been tightened in Hyderabad and Section 144 has been enforced in sensitive areas of the old city as several Muslim organizations have called for Black Day on Saturday to mark the 16th anniversary of demolition of the Babri Masjid in Ayodhya. Muslim organizations including Majlis-e-Ittehadul Muslimeen (MIM), Majlis Bachao Tehreek (MBT) and Darasgah-e-Jehad-O-Shahadat (DJS) have appealed to the Muslim community to observe a bandh Saturday as a mark of protest and to demand the reconstruction of the mosque. The Muslims will also hoist black flags on their roof tops and on the important crossroads. The deputy commissioner of police South Zone Atul Singh said that gathering of more than five persons will not be allowed and permission was not being granted for any meeting or procession tomorrow. The application of DJS for taking out a procession has been rejected by the police. The police has already gone on alert and elaborate arrangements were made for the Friday congregation. The DCP expressed his satisfaction that the Friday prayers passed off peacefully and expressed confidence that tomorrow will also pass without any untoward incident. As part of the security arrangements, two companies of Rapid Action Force, and 20 platoons of Andhra Pradesh Special Police along with the civil police have been deployed in the old city. The police patrolling was intensified and the bomb disposal units were also on alert. The police were also searching vehicles and passersby. The security has specially been tightened this time in view of Wednesday's incident in which three terror suspects opened fire on the police and injured two police constables. Though Hyderabad's Rajiv Gandhi International Airport doesn't figure on the list of three airports in the country facing the terrorist threat at present, the authorities were not ready to take any chance. The security in and around the airport at Shamsabad has been beefed up and no visitors were being allowed inside the airport.