A group of OSCE observers based in the Ukrainian city of Donetsk were out of contact for several hours after being detained. A separate group of observers missing since Monday remains unaccounted for.
The Organization for Security and Cooperation in Europe released a statement on Wednesday announcing it had lost contact with a group of 11 observers from the Special Monitoring Mission to Ukraine.
The group was traveling in three vehicles and was stopped at a road block in Marinka in eastern Ukraine.
Several hours later, contact was reestablished with the group as they returned to Donetsk.
The Danish government announced on Tuesday that a separate group of four OSCE observers was being held by armed separatists near Donetsk. This group went missing on Monday, Danish Trade Minister Mogens Jensen said Tuesday.
OSCE mission at risk
Veteran German diplomat Wolfgang Ischinger on Wednesday said the Organization for Security and Cooperation in Europe (OSCE) would consider withdrawing personnel from eastern Ukraine, unless the security situation improved.
"We do not know precisely where they are. On the basis of all we can infer, they are likely in the hands of one of the separatist groups," Ischinger told the German public broadcaster ZDF, referring to the group of four observers.
"If the security situation is such that one must fear for the lives of our employees, then I fear that we really would have to withdraw," Ischinger added.
Never again a 'Berlin Wall'
Ahead of talks with German Chancellor Angela Merkel in Berlin on Wednesday, Ukraine's Prime Minister Arseniy Yatsenyuk said people in his country wanted a "European perspective" on the dispute with Russia.
"The Berlin Wall has fallen and there will never be a new Berlin Wall in Europe," He said in a statement, standing with Merkel and his counterparts from Georgia and Moldova.
"Our goal is that Ukraine becomes a European country with the new president," he said, referring to the recently elected billionaire chocolate tycoon Petro Poroshenko. "The Ukrainian people expect change from us."
D-Day meeting possible
France, meanwhile, announced it had invited Ukraine's president-elect Poroshenko to the 70th anniversary commemoration of D-Day next week.
"We are very happy about the possibility to be able to take part in this special event in France," Poroshenko said in an interview Wednesday with the German newspaper Bild.
Russian President Vladimir Putin is also set to attend the June 6 ceremony in Normandy, meaning a meeting between the two is possible.
Poroshenko did not comment on a possible meeting in France.
"We will hold talks with Putin in order to ease the situation and make peace. When and where these talks will take place, is not yet decided," he said.
mz/dr (AP, AFP, Reuters)