CLEVELAND (REUTERS) - Cleveland police officials have tightened their security plan for the July 18-21 Republican National Convention as a result of the deadly shootings of police officers in Dallas, Deputy Police Chief Ed Tomba told Reuters on Friday.

Tomba, who is the city's chief of convention security, also said he had written to out-of-town police departments that will be loaning officers to Cleveland during the convention to assure them that their officers would be safe, adding that "we cannot pull the plan off without them".