Lucknow, March 14 :    Lucknow, March 14:  At least 21 youths were killed and three injured when the septic tank on which they were standing during an army recruitment in the cantonment area here collapsed this morning, police said. The issue rocked the Lok Sabha with Samajwadi Party members storming the well, demanding a statement from the government on the issue. As soon as the House assembled this morning, Samajwadi chief Mulayam Singh Yadav claimed that at least 50 youths had drowned and the situation there had become explosive. District magistrate Jeevash Nandan said the youths in the age group of 18 to 21 died when the tank gave way. The three injured were admitted to the Command Hospital, he said. The incident occurred around 5.10 am. However, an army spokesman said 18 youths were killed and three injured in the incident. All the 18 bodies have been brought to the Command Hospital. 'Rescue operations were carried out immediately. Many have been saved. But there are 21 deaths,' senior superintendent of police B.B. Bakshi said. He ruled out the possibility of any more person being trapped inside the sewage. 'Rescue operations are almost over. And we have seen that no more person is inside,' Bakshi added. The district magistrate said a magisterial enquiry has been ordered into the incident. The army has also ordered an inquiry. An army spokesman said the court of inquiry will be headed by the station commander of Lucknow. He has been asked to submit a report within 90 days, the spokesman added. Uttar Pradesh Governor Vishnu Kant Shastri announced an ex gratia of Rs 1 lakh each to the kin of the youths killed in the accident. Shastri expressed profound grief over the deaths, an official release said here. The Governor also announced a financial assistance of Rs 25,000 each to the injured, the release said, adding stern action would be taken against those found guilty. The Governor's secretary, V.N. Garg, visited the scene of the incident for an on-the-spot assessment of the situation. In the Lok Sabha, Deputy Speaker P.M. Sayeed told a protesting Samajwadi chief that he would be allowed to raise the matter during zero hour but Yadav insisted on an immediate government response. Amid protests from NDA members over the Yadav's attempts to disrupt the question hour, Samajwadi members trooped to the well shouting anti-government slogans such as 'Lalji Tandon ko giraftar karo (arrest Lalji Tandon)'. Tandon, they alleged, was responsible for the poor quality of the tank built during his tenure as Uttar Pradesh urban development minister. In a bid to pacify the members, former Prime Minister Chandra Shekhar appealed to the chair to allow Yadav to have his say so that the House could transact business. At one stage, Yadav asked his party men to return to their seats but in the face of remarks by some ruling NDA members, he directed them to return to the well. MDMK chief Vaiko and several other NDA members demanded suspension of Samajwadi members from the House for alleged violation of the code of conduct.