BAGHDAD - At least 47 people were killed and nearly 100 injured in two bomb attacks on Monday in eastern Iraq, security and medical sources said, underscoring a continued threat from Islamic State militants in a province previously considered freed of them.

In January Iraqi officials declared victory over the radical group in Diyala province, which borders Iran, after security forces and Shia paramilitaries drove them out of towns and villages there, but the militants have remained active. At least 40 people were killed and 72 others wounded when a car bomb exploded in a marketplace north of the city of Baquba, the sources said. A separate blast to the east of the city killed a further seven people and wounded 25.

There was no immediate claim of responsibility for the attacks, but they came less than a month after a bombing claimed by Islamic State in the nearby town of Khan Bani Saad, which left more than 100 people dead. Pro-government forces are struggling to uproot Islamic State from large swathes of territory in northern and western Iraq which the group seized in a sweep across the Syrian border last summer. “A suicide bomber driving a booby-trapped vehicle blew himself up in the middle of the central market area in Huwaydir,” a police lieutenant-colonel said. Another suicide bomber drove his explosives-laden vehicle past a checkpoint before blowing himself up in Kanaan district, killing at least 10 and wounding the same number, a police captain said.

An improvised explosive device also went off in a neighbourhood between Baquba and Huwaydir, killing three and wounding four, the same source said. It was not immediately clear how many of the victims were civilians.

Following the July 17 bombing in Khan Bani Saad, the provincial authorities had tightened security across the province, especially in Baquba which lies about 70 kilometres (45 miles) north of Baghdad.

The Khan Bani Saad blast came on the eve of the feast marking the end of the holy fasting month of Ramadan and shocked the nation.

There was no immediate claim of responsibility for Monday’s triple bombing, which bore all the hallmarks of the Islamic State group.

Baghdad announced in January that Iraqi forces had “liberated” Diyala, a religiously and ethnically mixed province which was partly overrun by IS after the jihadists launched a brutally effective offensive last June.