Yemeni authorities on Saturday arrested seven people accused of belonging to the Islamic State group (IS) - including one "Westerner" - in the second city of Aden, a police officer told AFP.

The arrests are part of a government offensive against al-Qaeda and IS, which has claimed a wave of deadly attacks in recent months in Yemen's south and southeast.

Among these were twin bombings claimed by IS that hit loyalist forces in Aden on Monday, killing at least 41 people as they queued to sign up as police recruits.

"We arrested seven Daesh [IS] members, among them a Western Muslim, in Mansura" district of Aden, said officer Munir al-Yafie, who took part in the raid, without giving further details.

A security source told local news site Aden al-Ghad that the cell of seven was led by a French national.

The group of seven was arrested during a dawn raid on a residential apartment.

The source said the group has been detained and is now subject to an investigation.

France is said to be the biggest source of European foreign fighters joining IS, with more than 900 French nationals thought to have left the country to fight for the group in Iraq or Syria.

It is not known how many French or European nationals could have joined the group in Yemen, where IS has not long had a presence.

Over recent months IS and al-Qaeda have made moves to exploit a power vacuum created by more than a year of conflict between pro-government forces and Houthi rebels to expand their zones of control in Yemen.

There has been an uptick in violence in the area since pro-government forces pushed al-Qaeda out of the nearby city of Mukalla, which they had controlled for over a year.

Following the advance of pro-government forces, IS claimed responsibility for a large bombing in the city followed by the deadly bombing targeting police recruits in Aden, leading to fears that IS could be attempting to fill a vacuum left by al-Qaeda and consolidate control at the expense of their militant rivals.

Government forces drove the Houthis rebels out of the port city of Aden and other southern provinces in July with support from a Saudi-led coalition, which launched a controversial bombing campaign in Yemen in March 2015.

But authorities have struggled to secure Aden, where Sunni militant groups consolidated their power after the Houthi left the city.

Aden has served as the temporary headquarters of Yemen's embattled government since the Houthis seized control of the capital Sanaa in September 2014.