Chennai, Feb 15 : The death toll in the fire at Tamil Nadu firecracker unit rose to 20 as one more person succumbed overnight to his injuries, officials said on Monday. J Vanaraja, 51, who had sustained 90 per cent burns, succumbed at the Government Rajaji Hospital in Madurai on Sunday night. Two more injured were said to be in 'critical' condition. A massive fire at Sree Mariyammal Fireworks near Sattur in Virudhunagar district on February 12, killing 11 persons and injuring more than 20 others. Meanwhile, officials have identified three more victim women -- M Poomari, 50, S Sankareswari, 55, and P Malliga, 58. Preliminary police investigations revealed that excess workforce along with illegal sub-leasing of the premises contributed to the disaster. Police has arrested one of the leaseholders, Ponnupandi, and are on the lookout for five others, including the factory owner. In a related development, Tamil Nadu Revenue Secretary K Phanindra Reddy has urged Petroleum and Explosives Safety Organisation to request the Centre to bring an amendment to the Explosives Act to prevent such disasters in the future. Reddy, who is also Commissioner of Revenue Administration, met with officials from various departments, including Virudhunagar Collector R Kannan, at the collectorate on Sunday and discussed ways and means to prevent recurrence of such fires. He also suggested that minimum qualification or training be made compulsory for workers employed at fireworks units. He asked officials to form teams of officials from various departments to carry out inspections at such units to ensure that these don't employ more workers than permitted. /IANS