OAKLAND -- After two weeks without a killing, police are investigating two homicides Thursday and the death of another man following a fight behind a house, all in East Oakland.

In response to the killings and at least two unrelated shootings Wednesday night and Thursday, Oakland Police Chief Sean Whent held an urgent meeting with his command team Thursday evening to deploy extra resources around the city Thursday night and Friday.

Captains will staff the department's mobile command unit through out the city and the Oakland Housing Authority will also have a mobile command unit out to assist police. Officers will do compliance checks with those on probation and parole, and special teams of crime-reduction and problem-solving officers will be out to lessen the chance for more crime and retaliatory violence, said Oakland police spokeswoman Officer Johnna Watson.

"This is the chief's new crime-reduction strategy," Watson said. "When crime trends and patterns are identified, resources in the city will be shifted to identify and arrest individuals responsible."

The latest slaying was about 3:15 p.m. at 84th Avenue and Dowling Street when a 19-year-old man was killed in a drive-by shooting. The name of the man, the 47th person killed in Oakland this year, was not immediately available. The man was walking from a friend's house when he was shot, police said.

Earlier Thursday, Kyal Porter, 24, of Oakland was shot while riding a bicycle at 5:32 a.m. in the 9800 block of A Street near International Boulevard. He was pronounced dead at the scene. Porter lived in a different part of East Oakland, not close to where he was found shot to death, police said.

More than a dozen shots had been fired, authorities said. Investigators were interviewing possible witnesses and reviewing video surveillance from cameras in the area looking for leads. No arrests had been made as of Thursday evening. Porter was the 46th homicide of the year.

The man who died following a brawl is a 34-year-old Oakland man who collapsed at 9:28 a.m. Thursday while fighting with another man in the back of a house in the 6300 block of MacArthur Boulevard in then the Millsmont neighborhood. The man was pronounced dead at the scene, but the cause of death will not be known until an autopsy is completed, police said.

Police did not release any information about whether an arrest was made.

Before Thursday, the last homicide in Oakland was June 12 when Aya Nakano, 22, of Emeryville was shot and killed on Market Street in North Oakland following a small car crash. No one has been arrested in that killing.

Police and Crime Stoppers of Oakland are offering as much as $10,000 in reward money for each homicide. Anyone with information should call police at 510-238-3821 or a tip line at 510-773-2805 or Crime Stoppers at 510-777-8572.

Contact Harry Harris at hharris@bayareanewsgroup.com. Follow him at Twitter.com/harryharris15. Contact David DeBolt at ddebolt@bayareanewsgroup.com. Follow him at Twitter.com/daviddebolt. Contact Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.