In a renewed threat to the region, IS attacked several remote villages and seized 30 locals from their homes, Ali al-Nawaf, a municipal council chief, told AFP.

"The bodies of seven of them have been found and security forces are searching for the others," he said.

The victims, in pictures posted on social media, were discovered with their hands tied behind their backs and eyes bound with red-and-white keffiyeh headscarves.

"This area used to be quite well-populated but it has emptied because it's become very dangerous for residents, who live off agriculture or as shepherds," said Nawaf.

He said residents could not defend themselves because their weapons had been confiscated, first by US-led forces which invaded Iraq in 2003, by IS from 2014 and then again by Iraqi security forces and their paramilitary allies.

The Shammar tribe to which the local residents belong was targeted by IS for having sided with the government in its battle with the jihadists, who were expelled from their last urban strongholds last year.

Despite the government's declaration last December of victory over IS, the jihadists have continued to carry out attacks in remote desert areas.

"There are sleeper cells in the Hatra region and the thousands of square kilometres of Jazira," the vast desert stretching from the west of Baghdad right up to the Syrian border, said Haytham al-Shammar, a tribal leader.

He said the jihadists were also infiltrating from Albu Kamal, a Syrian border town which the Damascus regime recaptured from IS earlier this month.

According to Nawaf, the jihadists have become emboldened in recent weeks, operating in daytime, not only at night, and travelling in larger road convoys.

"Now there are incidents every day," he said.

On Monday, IS killed three truck drivers in an attack on the highway linking Baghdad to oil-rich Kirkuk in the north, security sources said.

Iraq's Hashed al-Shaabi paramilitary force which has played a key role in fighting IS said 22 of its fighters were killed on Sunday night in an air strike near Albu Kamal just inside Syria.

Israel has declined to comment after its ally the United States implicated it in the attack which Baghdad and Damascus had blamed on Washington.