(CNN) — Clashes were reported Friday in Aleppo and Homs, two centers of opposition to Syrian government forces.
Here are the latest key developments in the nearly 18-month crisis:
On the ground: Shelling, violence continue
In Aleppo, the scene of fierce fighting in recent weeks, rebel fighters are clashing with government forces in the Saif al-Dawla, Hanano and Sakhour neighborhoods, the opposition Syrian Observatory for Human Rights said.
Regime forces are shelling several neighborhoods, it said.