ASTORIA, Queens (PIX11) — Six people were treated for carbon monoxide poisoning at a Queens restaurant Monday night, officials said.

Authorities discovered the carbon monoxide leak at Burgerology at 31-29 Ditmars Blvd. in Astoria at around 8:45 p.m., according to the FDNY. Two patients, including a worker and a patron, were taken to the hospital in critical condition, police said. Four people refused medical attention at the scene, police said.

It remained unclear what caused the leak, officials said.