BEIRUT — Gunmen attacked a pro-government TV station Wednesday near the Syrian capital, killing seven employees in the latest barrage of violence as world powers prepared for a high-level meeting that the US hopes will be a turning point in the crisis.

Invitations to Saturday’s gathering in Geneva were sent by special envoy Kofi Annan to the five permanent members of the UN Security Council — including Syrian allies Russia and China — but not to major regional players Iran and Saudi Arabia.