Likely retaliation for [1] yesterday's coordinated bombings and mortar shelling in Sadr City. The targeting of multiple Sunni mosques is obviously a considerable escalation. "Gunmen attack Sunni area in Baghdad: ministry" from [2] Reuters:

BAGHDAD (Reuters) - Gunmen attacked a Sunni enclave in a mainly Shi'ite district in Baghdad on Friday, burning four mosques and homes, an Interior Ministry official said.

The official said the number of casualties was not known, but a resident of Hurriya district said at least 18 people had been killed and 24 wounded.

"They attacked four mosques with rocket-propelled grenades and machinegun fire. The attacks began at midday," said the resident, who was helping to evacuate people from their homes.