German foreign ministry officials said Friday they had summoned Togo's ambassador in Berlin to demand an investigation into an attack on the German cultural center in the western African country, where violence has erupted following disputed weekend elections. "The government expects authorities in Lome to take all measures necessary to find out who was behind the attack and prevent any further attacks," a foreign ministry spokesman told AFP. The Goethe Institute in the Togolese capital was firebombed overnight by armed men. Goethe institute officials, at the organization's headquarters in Munich, said they were considering evacuating the director as well as stepping up security for the 13 remaining employees. The damage to the institute is estimated at 300,000 euros ($390,000) and the building is in danger of collapsing. The Togolese government has strongly criticized the German embassy in recent days, accusing it of supporting the opposition. Togo's former interior minister, Francois Esso Boko, who called for a delay in the presidential elections and was later sacked, is currently taking refuge in the Germany embassy.