A distributed swarm aggregation algorithm is developed for a team of multiple kinematic agents. Each agent is assigned with a control law which is the sum of two elements: a repulsive potential field, which is responsible for the collision avoidance objective, and an attractive potential field, that drives the agents to a configuration where they are close to each other and forces the agents that are initially located within the sensing radius of an agent to remain within this area for all time. In this way, the connectivity properties of the initially formed communication graph are rendered invariant for the trajectories of the closed loop system. It is shown that agents converge to a configuration where each agent is located at a bounded distance from each of its neighbors. The results are also extended to the case of nonholonomic kinematic agents and to the dynamic edge addition case, for which we derive a better bound in the swarm size than in the static case.