The latest video from Nigeria's Boko Haram Islamic extremist group shows the bodies of two beheaded men accused of spying, and copies some of the hallmarks of propaganda from the Islamic State group.

The SITE intelligence group said the video called "Harvest of Spies" was posted Monday on Twitter by Boko Haram's new media arm. The video is much slicker than previous ones and SITE said it borrows certain elements from IS productions, such as the sound of a beating heart and heavy breathing immediately before the execution.

Boko Haram has said in social media messages last month that it is considering swearing allegiance to IS.

Monday's video shows a man identified as Dawoud Muhammad of Baga city on his knees in the bush before several armed and masked fighters. In response to questions, Muhammad says a police officer paid him 5,000 naira ($25) to spy and promised to make him so rich he would never have to farm again. The other man is identified as Muhammad Awlu.

The video does not show the actual beheadings but the two bodies after the executions, with heads on the chests.

Boko Haram previously published only one beheading, of a Nigerian fighter pilot whose plane went missing in September.

Boko Haram's violent campaign in Nigeria killed at least 10,000 people last year, according to the Council on Foreign Affairs. At least 1.6 million people have been driven from their homes in the group's brutal 6-year uprising to create an Islamic state in Nigeria, Africa's most populous nation of 160 million people divided between mainly Muslims in the north and Christians in the south.

Boko Haram began emulating the Islamic State group last August, declaring it had established an Islamic caliphate in territory it controls in northeastern Nigeria.

In a major turnabout, Nigeria's military in recent weeks has wrested back a score of towns and villages that had been under the control of the insurgents for months.