Some 140 medical kits flown in from the United States arrived in southern Brazil on Saturday to treat survivors of the deadly disco fire who were exposed to dangerous fumes, authorities said.
The medication, called Cyanokit, was requested by the Brazilian health ministry to treat victims of last Sunday's fire who inhaled cyanide poison after the fire ignited acoustic foam insulation inside the "Kiss" nightclub.
The blaze left 236 people dead in the college town of Santa Maria in Rio Grande do Sul state.
About 20 people have been hospitalized with symptoms of chemical pneumonitis.
Another 123 people were hospitalized for other injuries sustained during the fire, which was ignited by a cheap flare lit by musicians as part of an illegal pyrotechnics display.
The medical kits flown into Santa Maria by a Brazilian Air Force plane were to be delivered to hospitals where survivors are being treated.
US Southern Command said it coordinated the transport of the medication, valued at $97,000, from the United States to Brasilia.
SOUTHCOM is responsible for US military operations in the Caribbean, Central America and South America.
Several Santa Maria parishes held services in memory of the fire victims.
In Rio, Archbishop Dom Orani Tempesta also celebrated Mass in their honor at the foot of the iconic Christ the Redeemer statue on Corcovado Mountain.
And officials reported that investigators have interviewed a total of 72 witnesses in connection with the tragedy.
On Friday, Rio Grande do Sul authorities extended for 30 days the detention of four people blamed for the Santa Maria tragedy.
The two owners of the "Kiss" nightclub and two musicians of the Gurizada Fandangueira group who allegedly took part in the ill-fated pyrotechnic show are also behind bars.
The authorities have also cited security violations at the club, including a lack of emergency lights, fire extinguishers that did not work and an overcrowded dance floor.
In the wake of the fire, several Brazilian cities announced more rigorous checks of clubs, bars and concert halls.
The tragedy is a huge embarrassment for Brazil as it prepares to host the 2014 World Cup and the 2016 Summer Olympic Games in Rio de Janeiro.