The killing of two men on Christmas in unrelated shootings had homicide investigators searching for the gunmen and motives yesterday.

One man, shot after buying a soda in a convenience store, apparently was killed as he resisted turning over his money to a robber. The other man was killed while leaving a party, police said.

It was about 7:30 p.m. when police were called to the 400 block of North 60th Street in West Philadelphia. Shawn McKnight, 35, of North Philadelphia, had been at his fiancee's home on Callowhill Street and had gone around the corner to buy a Mountain Dew at one of the few stores open in the area on the holiday.

Police said McKnight was heading back to the rowhouse, where his two young children had remained, when he was confronted by several men, at least one with a gun, on 60th Street.

Authorities believe that the men demanded money and that McKnight, who had a $20 bill in his hand, put up a struggle. He was shot in the chest with a 9mm gun, police said. The men fled without his money.

Police received a call about the gunshots and found McKnight bleeding and on the ground between two vehicles, about 100 feet from where he had been shot.

A detective said he might have attempted to hide from his assailants because he was partly under a parked truck. McKnight was taken to the Hospital of the University of Pennsylvania in a police cruiser and pronounced dead at 8:10 p.m., police said.

Friends and family had been concerned when McKnight did not return from the store and went to the crime scene only to learn that he had been shot.

A woman who lives nearby and asked that her name not be used said she hears gunshots on a weekly basis and fears for the safety of her sons. On Christmas night, she said, she heard the commotion outside her home.

Less than three hours later, Andrew Jackson, 44, of North Philadelphia, was leaving a party in the 2300 block of Oakdale Street about 9:50 p.m.

Police said he was ambushed at close range and shot several times. Authorities believe Jackson was the intended target, but said yesterday they were trying to determine a motive.

Anyone with information about either killing is being asked to call homicide detectives at 215-686-3334.

The homicides are among 390 reported this year. Last year during the same period there were 401 killings reported. Last year was the first time since 1997 that the city had more than 400 homicides in one year.