The prosecutor of the International Criminal Court (ICC) on Monday announced a preliminary probe of possible crimes against humanity committed in Libya, after a referral by the United Nations.
He was "assessing allegations of widespread or systematic attacks against the civilian population," prosecutor Luis Moreno-Ocampo told journalists in The Hague, adding "this could constitute crimes against humanity and must stop".
The office of the prosecutor will decide "within a few days", after completing this preliminary assessment, whether or not to launch a full investigation of alleged crimes committed in Libya since February 15, he added.
This would enable prosecutors to "collect evidence and request an arrest warrant against those identified as the most responsible. The judges will then decide based on the evidence."
Moreno-Ocampo promised that the court would move "swiftly and impartially," saying, "There will be no impunity for leaders involved in the commission of crimes."
The U.N. Security Council on Saturday referred the situation in Libya to the ICC, saying "the widespread and systematic attacks currently taking place against the civilian population may amount to crimes against humanity."
Libyan security forces have cracked down on protests that started nearly two weeks ago against the 41-year regime of Muammar Gaddafi.
The unrest has killed at least 1,000 people and set off a "humanitarian emergency", the U.N refugee agency UNHCR said, as almost 100,000 people, mostly migrant workers, fled the North African state.
Among the issues that the prosecutor will consider is the nature of the alleged crimes as the court has jurisdiction only over war crimes, crimes against humanity and genocide.
"If people were in a square and were attacked by tanks, planes and soldiers, and if people were killed in a systematic way, this was a crime against humanity," said Moreno-Ocampo.
If the prosecutor decides to open an investigation, they may request from an ICC pre-trial chamber to deliver warrants of arrest or summonses to appear for people that may bear the highest responsibility for the alleged crimes.
This is the second time that the U.N. Security Council refers a case to the ICC; the first was alleged human rights violations committed in Darfur.
That referral led to warrants of arrest being issued against Sudanese President Omar al-Bashir for genocide, war crimes and crimes against humanity.
The ICC is the world's only independent, permanent tribunal with the jurisdiction to try genocide, crimes against humanity and war crimes.
In most cases, the court opens its own investigations or has them referred by signatory states to its founding Rome Statute, which Libya is not.