Palo Alto police are increasing their overnight patrols in residential neighborhoods after learning about an attempted burglary that they say occurred on Fulton Street on Sunday morning, the fourth such incident in the last two weeks.

Police said the latest incident occurred in the 1100 block of Fulton Street, a block away from Middlefield Road. A woman in her 70s called the dispatch center at 5:23 a.m to report that she had been awakened by the sound of "rattling" at her back door, according to a Palo Alto Police Department news release. When she went to investigate, the woman allegedly heard the sound of someone running from her side yard. She then called the police.

The investigation showed that the intruder entered the home's rear yard through an unlocked side yard gate and then removed two screens from windows, police said. The person may have also slid open a window that was left ajar, according to the news release.

Police searched the neighborhood with a canine from the Sunnyvale Department of Public Safety but could not locate the intruder, who remains at large, police said. There is no surveillance video of the incident.

Police said they are increasing patrols and investigating possible links between the Sunday incident and the other three recent ones that occurred in Palo Alto. In those cases, residents remained asleep and discovered personal property missing when they awoke. Police are also looking at similar crimes that have been reported in other cities, the news release states. As of Monday morning, it is unknown if all four Palo Alto cases are related, the news release states.

There have not been any confrontations between suspects and residents in the Palo Alto cases, police said, and no evidence that the suspects had entered occupied bedrooms. The news release notes that overnight residential burglaries remain extremely rare in Palo Alto, with most burglaries occurring during the day, when homes are unoccupied.

Police are recommending that residents put locks on side yard gates and secure all windows and doors overnight. Additional tips are available at cityofpaloalto.org/StopCrime.

Anyone with information about this incident is asked to call the department's 24-hour dispatch center at 650-329-2413. Anonymous tips can be emailed to paloalto@tipnow.org or sent by text message or voicemail to 650-383-8984. Tips can also be submitted anonymously through the police's free mobile app, downloadable at bit.ly/PAPD-AppStore or bit.ly/PAPD-GooglePlay.