French judges have issued arrest warrants for Bashar al-Assad, the former Syrian ruler, and six senior officials of his ousted regime, for killing and wounding a group of journalists, including the American Marie Colvin, in 2012, during the Syrian civil war.

Ms. Colvin, 56, a reporter for the British newspaper The Sunday Times, and Rémi Ochlik, 28, a French freelance photographer, were killed when artillery struck a building in Homs where journalists had set up a makeshift media center. Three others were wounded. Colleagues suspected that Syrian forces had located the journalists by tracing their satellite phone signals.

The judges of the French War Crimes Unit who investigated the attack found that the seven men named in the warrants were likely to be guilty of a war crime and a crime against humanity, according to the Paris-based International Federation for Human Rights, which is involved in the case. The warrants were issued on Aug. 22 but first revealed on Tuesday by the federation; the judges, themselves, have not made any public statement.

The French investigation revealed that the Syrian officials ordered the targeting of civilians during the brutal siege of the city of Homs, regarded as a rebel stronghold, and that there was a Syrian government policy to stop international journalists from covering the conflict, said Clémence Bectarte, a lawyer for the human rights group and for the parents of Mr. Ochlik.

“The judges had access to documents from the security services at the time ordering that journalists be followed and intercepted at checkpoints,” she said. Even so, some foreign reporters and photographers managed to slip into the city to cover the carnage and the destruction there.

Mr. al-Assad and his family fled to Russia last December, and the whereabouts of the six other accused officials are unknown, but under French law they can be tried in absentia.