From the description of Ranged (p 271)
- Provoke Opportunity Attacks: If you use a ranged
power while adjacent to an enemy, that enemy can
make an opportunity attack against you.
From the description of Area (p 271)
- Provoke Opportunity Attacks: If you use an area
power while adjacent to an enemy, that enemy can
make an opportunity attack against you.
The rules for Ranged and Area powers are covered under attacks (because most are technically attack powers) but apply the same way to powers that are not attacks.
This, by the way, is why Inspiring Word and Healing Word are Close burst X powers with Target: You or an ally and not Ranged X powers with Target: You or an ally... specifically so they do not trigger OAs.
Also from Opportunity Attacks (p 290):
Ranged and Area Powers Provoke: If an enemy
adjacent to you uses a ranged power or an area
power, you can make an opportunity attack against
that enemy.