SYDNEY — A boat carrying around 150 asylum seekers capsized in the Indian Ocean, spilling men, women and infants into rough waters and killing four people, Australian officials said Wednesday.

The boat rolled over Tuesday in choppy seas 125 kilometers (78 miles) north of Christmas Island, Home Affairs Minister Jason Clare told reporters. The Australian island is 500 kilometers (310 miles) south of Jakarta, Indonesia.

Two navy ships had been sent to assist the vessel earlier in the day, but rescue crews were unable to board as waves reached as high as 4 meters (13 feet), said David Johnston, Commander of Australia's Border Protection Command.

The navy ships instead began escorting the boat to Christmas Island, where Australia operates a detention camp for asylum seekers. Several hours into the journey, the boat started leaning and some passengers began jumping into the water. Shortly after, the boat rolled and capsized, Clare said. Officials don't know what caused the boat to flip.

Rescuers dropped life rafts into the water and plucked 144 people to safety. The bodies of two women and two men were recovered before the search was called off Tuesday night.

The survivors, from Afghanistan, Pakistan, Iran and Iraq, were taken to Christmas Island, along with three Indonesian crew members. There were several infants and children on board, Johnston said.

"It is a dreadful feeling in the stomach when we hear that a vessel has capsized, or that it is in some difficulty," Johnston said. "Recovering 144 people in the conditions they had yesterday was extraordinary work."

Customs officials estimated the boat had 150 passengers and said they are interviewing survivors to determine the exact occupancy of the boat but aren't searching for more people.

Christmas Island is a popular destination for asylum seekers who crowd into rickety boats at Indonesian ports and pay people smugglers to ferry them to Australian shores. Hundreds have died while attempting the journey in recent years.

Last week, another boat carrying asylum seekers sank off Christmas Island. Officials recovered the body of a baby boy and were unable to find 8 passengers who vanished in the water.