FACTBOX: Who is responsible for civilian deaths in Afghanistan?

(Reuters) - At least seven children have been killed in a U.S.-led coalition air strike on a religious school in Afghanistan, the coalition said on Monday, amid rising anger over civilian deaths from foreign military operations.

Some 1,500 of the 6,000 people who have been killed in Afghanistan over the past 17 months have been civilians, with last year the deadliest for civilians since the fall of the Taliban in 2001, Human Rights Watch said.*

Here is an overview of the groups believed responsible.

* TALIBAN:

-- After the U.S. ousted the Taliban government in November 2001, forces regrouped in their historic stronghold, the southern ethnic Pashtun provinces. The Taliban are thought responsible for the majority of suicide attacks in 2006, in which some 803 Afghan civilians were killed or injured (272 killed and 531 injured).

-- Spokesmen often justify attacks as permissible against supporters the government of Hamid Karzai.

-- Ex-leader of the Taliban government, Mullah Mohammad Omar, is the supreme authority for the movement, which has lost several top military figures in the past seven months. If alive, the low-profile Jalaluddin Haqqani is widely believed to be military commander.

-- Analysts say up to 40 militant foreign groups support the movement, and that disparate groups can mobilize between 5,000 and 15,000 troops, including Pashtun tribal militias.

* HEZB-I- ISLAMI:

-- "The Islamic Party" is led by Afghan warlord Gulbuddin Hekmatyar, an university-trained engineer who was one of the leading insurgent commanders who fought the Soviet-backed communist government in the 1980s and early 1990s, and was notorious for shelling and rocket attacks on Kabul in the 1990s.

-- Forced into exile when the Taliban conquered Kabul in 1996, Hekmatyr has moved on from bitter rivalry with the Taliban to publicly announcing they would work together against the government and international forces.

* ANTI-GOVERNMENT ELEMENTS (AGE):

-- The acronym AGE is used by the Afghan government and allied forces to describe a number of armed insurgent groups.

-- These include tribal militias contesting central government authority, criminal networks such as opium cartels involved in the booming narcotics trade, and smaller groups associated with Taliban or Hezb-i- Islami, like Jaish al Muslemin, the "Army of Muslims".

* NATO/INTERNATIONAL FORCES:

-- Roughly 38,000 of the nearly 50,000 international troops in Afghanistan are under the UN-mandated and NATO-led International Security Assistance Force (ISAF). Stationed in Kabul and various provinces, the largest concentrations are in the south.