BERLIN (Reuters) - Germany said on Friday it had no knowledge of U.S. drone strikes being directed from its territory after media reports alleged that the U.S. military was steering attacks on Islamist guerrillas in Africa from German bases.

The use of drones is highly controversial in Germany, where an aversion to military conflict has prevailed since World War Two, and the reports sparked a strong response from opposition parties hoping to score points against popular Chancellor Angela Merkel ahead of a September election.

Thomas Oppermann, parliamentary floor leader of the center-left Social Democrats (SPD), said German law prohibited targeted attacks outside of armed conflicts and demanded an explanation from the government.

“The German government has no knowledge of such operations being planned or carried out by U.S. armed forces,” Merkel’s spokesman, Steffen Seibert, told a regular government news conference.

Asked about the reports, Major Ryan Donald of United States European Command (EUCOM) based in Stuttgart said: “We maintain robust civilian and military cooperation with Germany and manage all base activities in accordance with the agreements made between the United States and German governments.”

“The Air and Space Operations Center at Ramstein Air Base monitors and assesses assigned airpower missions throughout Europe and Africa, but does not directly fly or control any manned or remotely piloted aircraft,” he said in a statement.

The Sueddeutsche Zeitung newspaper, one of several news outlets to carry the reports, said the U.S. military had directed drone attacks against suspected Islamist guerrillas in Somalia and other African countries from its Africom command in Stuttgart and air force base in Ramstein.

The paper quoted German legal expert Thilo Marauhn saying that Germany’s constitution forbade it from having any role in the killing of suspected terrorism suspects outside the theatre of war.

Oppermann said he would pursue the issue in a parliamentary oversight committee. The pacifist Left Party demanded the closure of all U.S. bases on German territory following the reports.

After months of criticism over civilian casualties linked to U.S. drone strikes, U.S. President Barack Obama announced tighter limits on the use of remote-controlled unmanned aerial vehicles last week.

Martin Schaefer, a spokesman for the German foreign ministry, declined to offer an outright condemnation of drones, suggesting their use could be justified in certain circumstances.