A large fire at a chlorine chemical plant in Hudson County continues to burn Saturday morning and although it is under control, authorities have kept the Pulaski Skyway closed in both directions and continue to test the air quality to ensure the air is safe to breathe.

During the early-morning hours on Saturday, local residents in several towns and cities were urged to remain indoors because of the potential danger from chemical fumes.

“If you are outside and you smell smoke, go back inside,” Kearny Fire Chief Steve Dyl said in an interview with ABC7 in New York at about 7:30 a.m.

Another representative of the Kearny Fire Department said the blaze is under control, but there still are some hot spots burning at the chemical plant. Some local streets remain closed, as of 8:20 a.m., and the Pulaski Skyway remains closed.

UPDATE (10:10 a.m. Saturday): Kearny police say it is now safe for residents in their town to open their windows or go outside.

“In Kearny, there’s no air quality issue,” said town police Lt. Charles Smith. “We have a hazmat unit out testing the air.”

Smith said the wind appears to be blowing toward Newark and Jersey City, so officials in those cities will have to determine if the air is safe in that region. As of 10:10 a.m., the Pulaski Skyway remained closed to traffic, along with truck Route 1 and 9 and some local streets in South Kearny, Smith said.

UPDATE (10:55 a.m. Saturday):

At about 10:40 a.m., a Jersey City police spokeswoman said the air quality in that city is fine.

“Air samples specific to the Greenville, Society Hill and Lincoln Park areas have now been deemed safe," she said, adding that the Jersey City Fire Department will continue to test the air, and city officials are awaiting information from state officials.

Earlier air quality alerts

Late Friday night, when the blaze broke out at the Alden Leeds chemical company on Jacobus Avenue in Kearny, officials from Kearny, Bayonne, Hoboken and Newark all urged residents in their towns to remain inside their homes and to keep their windows closed because huge plumes of smoke were drifting over the region.

Some smoke also drifted over parts of Staten Island in New York.

As of 7:45 a.m., both directions of the Pulaski Skyway remained closed. The Skyway, which carries traffic on Routes 1 and 9 between Newark and Jersey City, is located very close to the chemical plant.

So far, there have been no reports of any injuries, and the cause of the fire has not been determined.

Hoboken officials say it is safe for residents of their city to open their windows, because “the air does not pose any sort of health risk.” The air advisory has also been lifted in Bayonne.

Fortunately due to SE winds, smoke and fumes from last night's in Kearny never made there way to Hoboken. It has been deemed safe to reopen your windows and the air does not pose any sort of health risk. **All city actives remain on schedule.**https://t.co/s9ez4hsMx8 — City of Hoboken (@CityofHoboken) May 18, 2019

In Newark, the police department sent this message out on its Twitter feed at 12:09 a.m. Saturday: "Newark Public Safety Director Anthony F. Ambrose reports that a large chemical fire in South Kearny may be sending fumes into Newark. People in impacted areas are urged to keep windows and doors shut and stay inside. The fire is under the Pulaski Skyway near Ironbound section.”

A similar message was posted on the police department’s Facebook page, which noted some firefighters from Newark were helping to battle the Kearny blaze.

As of 2:50 p.m. Saturday, no updates were posted by Newark police, and city officials could not be reached for comment.

The Alden Leeds facility manufactures and stores chlorine, which is used in industrial processes and as an antiseptic. Is it not immediately known what caused the fire, which sent large giant plumes of thick gray smoke billowing over the Pulaski Skyway and area towns Friday night.

Chlorine fire on the #pulaskiskyway. Bridge is at a complete standstill. Police and Fire Department are not letting anyone through. pic.twitter.com/tTWpKKE9ir — The English American (@an_esq10) May 18, 2019

#FDNY Marine 6 operating at a chemical plant fire at 55 Jacobus St in #Kearney, NJ last night. pic.twitter.com/gQRshVgwCW — NYCFireWire (@NYCFireWire) May 18, 2019

NJ Advance Media staff writer Olivia Rizzo contributed to this report. Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.