The city recorded a double-digit increase in murders during 2010, with more than half the victims shot to death by someone they knew in cases likely related to drugs, according to preliminary NYPD statistics released yesterday.

As of Dec. 31, there were 532 murders, up 13 percent from 2009. Rape, robbery and felony assault were all also up, but overall crime was down 2 percent.

NYPD officials say the numbers, although a concern, aren’t overly alarming when put in the context of dramatic crime-fighting gains since 1990. The city had a record 2,245 homicides that year.

And the 2010 figure for murder is still the fourth lowest since the department began keeping comparable records in 1962. The lowest was last year, at 471.