KIEV, Ukraine — Separatist rebels in the east of Ukraine have resumed the use of rocket launchers that should have been withdrawn under a February peace deal, Ukrainian military officials said Tuesday.
The army said in a statement that rebels fired Grad rockets Monday evening at the government-held town of Avdiivka, which lies on the fringes of the main rebel stronghold of Donetsk.
There has been a recent uptick in clashes along the front separating government and rebel forces. Speaking at an investor conference in Kiev, President Petro Poroshenko warned that the resumption of full-blown war is a perennial threat.
"War could start at any moment, but we are ready to do everything possible to dispel any room for doubts or retreats," he said.
Oleksandr Motuzyanyk, military spokesman for the Ukrainian presidential administration, said one soldier had been killed and 14 injured during the past day's unrest. He gave no details on where casualties had been sustained.
"The geography of cease-fire violations by militia has broadened. For the first time this month, the enemy has deployed the Grad system against our servicemen,"Motuzyanyk said.
Eduard Basurin, the spokesman for separatist forces in Donetsk, in turn accused Ukrainian forces of dozens of cease-fire violations. Organization for Security and Cooperation in Europe observations on craters created by recent impacts in the rebel-held village of Nova Marivka confirmed that Ukrainians troops had been using 152-mm artillery shells, Basurin said.
More than 6,000 people have died and a million have been displaced by the conflict that has raged over the past year.
A cease-fire tortuously negotiated by France, Germany and Russia in Minsk, the capital of Belarus, requires the warring sides to pull back their most powerful arms by distances over 50 kilometers (30 miles).
Responsibility for checking whether the deal is being implemented lies with the OSCE, but its special monitoring mission said late Monday that its monitors have been prevented by rebels from visiting a location where heavy arms have allegedly been deployed.
For the third time in four days, the rebels have prevented the mission "from freely accessing the eastern part of Shyrokyne," the OSCE said in statement.
Shyrokyne lies directly on the front line and is a short distance east of the key industrial port city of Mariupol, which is in government hands.
Fighting there has never entirely subsided despite the Minsk agreement, but clashes appear to have intensified in recent days.
The OSCE has said the clashes it saw Sunday in Shyrokyne were the worst it had seen since fighting began in the area in mid-February.
The mission said it observed dozens of tank shots and the deployment of plenty of other weapons proscribed under the peace deal.
U.S. State Department spokesman Jeff Rathke said in Washington that Russia has deployed more air defense systems into eastern Ukraine and positioned several near the front lines.
Russian Defense Ministry spokesman Gen.-Maj. Igor Konashenkov on Tuesday denied that Russia has any air defense systems in Ukraine. He also repeated claims that U.S. military trainers are working with Ukrainian forces in the conflict zone.
Kiev would like to see international peacekeepers on the ground, but that proposal has been greeted with hostility by Russia and coolness by Western countries.