Delhi Police on Wednesday arrested Lavkesh Bajaj, owner of the building that housed the Flourish Stay B&B in Malviya Nagar. This came hours after a massive fire killed 21 people and exposed alleged violations of fire safety and building regulations. Track live updates hereBuilding owner Lavkesh Bajaj arrested by the Delhi Police in connection with Malviya Nagar fire incident. (Delhi Police via ANI)The blaze erupted early Wednesday at the five-storey guest house in the congested Hauz Rani area of south Delhi. Among the 21 killed, 18 were foreigners from African nations, Bangladesh, Afghanistan and more.Police had earlier issued a lookout circular against Bajaj and his wife before launching a search operation to trace them. An FIR has been registered under charges of culpable homicide and other relevant provisions of the Bharatiya Nyaya Sanhita, PTI reported.How the fire occuredInvestigations and statements by Delhi home minister Ashish Sood suggest the guest house was operating without the mandatory fire no-objection certificate (NOC) and in violation of multiple safety norms.ALSO READ | Delhi fire: Hotel under scanner, owner detained, 18 foreign nationals killedOfficials said the building had only one entry-exit point, permanently sealed windows and a sensor-operated main door, conditions that are believed to have severely hindered evacuation efforts as the fire spread rapidly through the structure.Investigators have also alleged that the establishment was operating far beyond its approved capacity. According to police sources, the property had permission for only six rooms under Delhi government's Bed and Breakfast policy but was allegedly running around 25 rooms, including some in the basement.Additional floors were reportedly added over the years without obtaining the required approvals from authorities.Inspection drive orderedDelhi lieutenant governor Taranjit Singh Sandhu has ordered a month-long inspection drive covering hotels, nursing homes, coaching centres, restaurants and other vulnerable commercial establishments.ALSO READ | ‘No ventilation’ in shaft-like building, chilling escape video: 5 shocking details in Delhi Malviya Nagar fireSeparately, home minister Ashish Sood directed a citywide verification of Bed and Breakfast properties by the Delhi Fire Services and the Power Department.Chief minister Rekha Gupta said the government was closely monitoring the situation and has sought a detailed report on the incident, while opposition leaders criticised the administration over recurring fire-related tragedies in the national capital.Police said the investigation remains underway and the role of other individuals associated with the guest house is also being examined.