ADDIS ABABA -- Ethiopia protested Saturday to the UN mission in Ethiopia and Eritrea (UNMEE), which has accused Ethiopian forces of making incursions into a UN-protected buffer zone separating the two countries.

Ethiopia says its soldiers have been playing football in the 25-kilometer (15-mile) wide Temporary Security Zone (TSZ) and has denied that the forays into the belt were motivated by anything other than finding a good pitch.

"Tension on the border between Ethiopia and Eritrea has increased after UNMEE officials protested to Ethiopian government on Thursday over what they said was repeated border incursions by Ethiopian troops into Eritrea," Ethiopian Information Ministry spokesman Zemedkun Tekle said.

"UNMEE has repeatedly asked both parties to get closer and open talks, but now is strictly trying to stop an unarmed Ethiopian army from playing football inside the TSZ and taking the incidents very seriously instead of trying to solve the major problem between the two parties," Zemedkun said.

"The reason for the Ethiopian army to play football inside the TSZ is only to find a better place to play the game and had no other political reasons behind it," he added.

The TSZ runs 1,000 kilometers (around 620 miles) along the Ethiopia-Eritrea border and is overseen by some 4,200 UN troops, mandated to monitor and protect the buffer zone. Under the Cessation of Hostilities Agreement signed between Addis Ababa and Asmara in June 2000, the two countries' armed forces are strictly forbidden from entering the zone.