Attacks and clashes in Iraq killed 16 soldiers and police overnight, as the country struggles to contain its worst violence in years.

Attacks and clashes in Iraq killed 16 soldiers and police overnight, as the country struggles to contain its worst violence in years, officials and doctors said Saturday.

And gunmen held part of the northern town of Sulaiman Bek, after security forces withdrew despite reportedly making gains in the area on Friday.

Five soldiers were killed during clashes with militants in the Jurf al-Sakhr area south of Baghdad on Friday night, while a bomb killed five police in Baiji, north of the capital.

Gunmen also killed a police colonel in his home in the city of Tikrit, also north of Baghdad, and shot dead four soldiers on the area's main highway.

And militants killed a police captain who was attempting to evacuate his family from the town of Sulaiman Bek.

Security forces are frequently targeted with bombings and shootings by militants opposed to the government.

Militants initially seized part of Sulaiman Bek and nearby areas in Salaheddin province Thursday, but officials said security forces gained ground in heavy fighting the following day.

On Saturday, gunmen were in control of the town's Al-Askari neighborhood, he said.

Sulaiman Bek has been hit by numerous attacks over the past year, and was briefly seized by militants in late April.