( dpa )- An Iraqi army force discovered a weapons cache including plane engines and containers of TNT explosives in the central Iraqi Diyala province where another grave was also uncovered.
A force from the 5th division of the Iraqi army found the cache in the Uthmaniyah area containing 29 plane engines, four of which are unused, and 90 containers full of TNT explosives, the Voices of Iraq (VOI) quoted a statement by the Iraqi military news agency as saying.
The statement did not say when the cache was found.
Also in Diyala , Iraqi troops uncovered a grave containing six bodies of unidentified civilians, who are believed to have been collectively executed by shooting, a security official told VOI.
The grave was found in the Qurayshat village in Khalis a day after a big mass grave was discovered nearby in the same area.
About 100 decomposed bodies were found in the Khalis grave - one of the largest such finds in several months.
The US and Iraqi officials said the skeletal condition of the bodies indicated that they may have been there for a long time.
Diyala is one of Iraq's most restive provinces and is a central stage for extremist Sunni insurgents from the Islamic State of Iraq group linked to the al-Qaeda terrorist network.
In the neighbouring Salahaddin province, a policeman was killed and three others injured in a bomb attack in Tikrit , VOI reported.
The attack in central Tikrit occurred in tandem with two assaults targeting police patrols in other parts of the city. No casualties were reported in the two blasts but shops were damaged.
Further north in Ninenveh province, two civilians were killed and five injured by a car bomb in central Mosul .
A car parked in a garage was detonated by remote control in the Corniche area of central Mosul , 400 kilometres north of Baghdad, General Khaled Abdel-Sattar , the spokesman of the Nineveh operation command told VOI.
Nineveh has recently seen a surge in violence after insurgents driven out of Baghdad and neighbouring areas started regrouping in the province.
Earlier, Iraqi authorities announced new steps to ensure the legality of the residence permits of foreigners living in the capital as part of a plan to quell violence in Baghdad.
Security checkpoints all over Baghdad have received orders to check the validity of residence documents held by Arab and foreign nationals and accredit legal ones, Major-General Qasim Atta , the spokesman for the Baghdad operations command, told VOI.
"Those who do not have valid documents will be held accountable," Atta said.
Since the 2003 US-led war on Iraq, hundreds of Arab nationals have been crossing into Iraq from neighbouring countries to take part in the insurgency against foreign and Iraqi troops.
The US and Iraq say many of those foreign fighters are loyalists of the al-Qaeda.
But the influx of foreign insurgents is believed to have ebbed after Iraq signed security cooperation agreements with neighbouring Syria.