Russian President Vladimir Putin telephoned his Armenian and Azerbaijani counterparts on Tuesday to call for an immediate end to heavy fighting in Nagorno-Karabakh that has killed dozens of soldiers from both sides.

In a statement, the Kremlin said Putin reiterated his concerns regarding the worst escalation of the Karabakh conflict since 1994 and “urged both sides to urgently ensure a full cessation of hostilities and observance of the ceasefire regime.”

“It was pointed out that Russia is taking and will continue to take necessary mediating steps to help normalize the situation,” said the statement. It said Putin also stressed the need to resume Armenian-Azerbaijani peace talks under the aegis of the OSCE Minsk Group co-headed by Russia, the United States and France.

“It was agreed that contacts should continue in different formats,” the statement added without elaborating.

With official Armenian and Azerbaijani sources giving no further details of the phone calls, it was not clear whether Putin sought to organize a meeting of Presidents Serzh Sarkisian and Ilham Aliyev.

Sarkisian is scheduled to travel to Germany on Wednesday on a two-day official visit that will involve talks with German Chancellor Angela Merkel and Foreign Minister Frank-Walter Steinmeier.

The phone conversations were reported several hours after the two warring sides said they have agreed to halt hostilities along “the line of contact” around Karabakh at noon. A spokesman for the Karabakh Armenian army said on Tuesday evening that the intensity of fighting decreased even though Azerbaijani forces continued to shell Armenian positions at different sections of the frontline.

Putin was quick to express through his press secretary serious concern after the Azerbaijani army launched an offensive at different sections of the Karabakh frontline early on Saturday. Despite its close military and political ties with Armenia, Moscow has been careful not to publicly blame Baku for the fighting or pledge support for the Armenian side.

The Russian military began on Tuesday five-day exercises in Russia’s southern Dagestan region bordering Azerbaijan. It was not clear whether the drills reportedly involving about 1,000 soldiers as well as dozens of tanks and artillery systems were planned beforehand or are connected with the Karabakh escalation.