KIEV, June 12 - Seven Ukrainian soldiers were killed in just three days in renewed fighting with pro-Russian rebels in the east of the country, the military said Monday.

Four soldiers were killed on Saturday, two Sunday and one on Monday, bringing the death toll to 14 since the beginning of June, AFP reported.

"The escalation began two to three weeks ago, the enemy is sending heavy weapons to frontline positions which is a violation of the peace agreements," military spokesman Andriy Lysenko told journalists.

The developments come five days after Ukrainian officials citing intelligence reports said pro-Russian separatists have been preparing for a massive offensive.

The officials also said the rebels have been using Russian-made drones for targeting Ukrainian troops with heavy artillery.

President Petro Poroshenko told OSCE Chairman Sebastian Kurz at a meeting in Kiev last week that security situation have aggravated in the region.

"It’s a brutal violation by the Kremlin of the Minsk agreements as evidenced by the aggravation of the security and humanitarian situation in the Donbas,” Poroshenko said.

Poroshenko called for a special armed police mission from the Organization for Security and Cooperation in Europe to monitor the region in order to stop the fighting.

The presence of the armed OSCE police mission in the occupied territories would help bring stability and end the fighting and start the process of returning the regions under the control of Ukraine.

Russia has been actively opposing any armed OSCE police mission in Luhansk and Donetsk, but has apparently agreed to arm OSCE monitoring teams on the frontline.

More than 10,000 people have died since the pro-Russian insurgency began in April 2014, which Kiev and the West accuse Moscow of masterminding.

The US and EU have imposed sanctions on Russia, but Russia has denied backing the rebels.

Efforts to secure a peace deal have ground to a halt as the fighting has dragged on, and neither side appears prepared to make concessions.

The conflict, along with Russia's annexation of Crimea from Ukraine in 2014, has pushed ties between Moscow and the West to their lowest point since the Cold War. (afp/nr/ez)