CHERRYLAND -- A pregnant woman who was hospitalized after gunmen reportedly rammed her truck and robbed her Monday afternoon was released from care Tuesday in good condition, an Alameda County Sheriff's Office spokesman said.

Sheriff's Office investigators now believe four men were involved in ramming the woman's car at Western Boulevard near the intersection of Willow Avenue about 2 p.m. on Monday. Sgt. Raymond Kelly said. Earlier, officials had said the attack was pulled off by two gunmen.

The driver, a 40-year-old woman who has reached the full term of her pregnancy, emerged OK, as did her unborn child, Kelly said. The woman was found by deputies in the driver's seat of her vehicle, which had been pushed onto railroad tracks.

The woman told deputies that she saw two of the men, in their mid 20s between 5 feet 8 inches and 5 feet 10 inches tall and wearing all black clothing, after they rammed her car at full speed until it was on the tracks, Kelly said. Then one of the suspected robbers, showing a gun, grabbed her purse and a bag of laundry before taking off in the truck westbound on Willow Avenue.

Kelly said Tuesday that investigators believe four men were involved. Sheriff's Office authorities did not have a description of the other two.

According to Kelly, the getaway truck was damaged severely from crashing into the woman's vehicle and broke down about two blocks away on Willow Avenue. The men involved then ran away on foot.

Anyone with information about the robbery should contact the Alameda County Sheriff's Office at 510-667-3651.