A German ship carrying Iranian weapons was stopped in the Mediterranean on Saturday, according to a report by Der Spiegel.

The ship, weighing 6,200 tons, was carrying weapons and ammunition to Tartus, Syria with the aim of arming President Bashar Assad's forces, the report said.

It docked a few days ago in Djibouti in the Horn of Africa, where it was loaded with weapons supplied by an Iranian cargo ship.

The ship was identified by Syrian defectors, who contacted the German shipping company. The company then ordered the ship to change course, and although it started heading toward Turkey is was eventually halted 80 kilometers southwest of Tartus.

The German government said it was looking into the report, and its Economy Ministry said it was "investigating whether the ship broke an embargo on Syria."

Der Spiegel quoted shipping agent Torsten Lueddeke of Hamburg-based C.E.G.
Bulk Chartering as saying: "We stopped the ship after we received information
on the weapons cargo."

He said the ship was chartered to Ukraine-based White Whale Shipping, and they said the ship was carrying pumps and similar equipment.

The Ukrainian company denied the ship was carrying any military cargo or weapons, saying instead that it was loaded in India with electronics and was headed for Turkey.

The boat is due to dock in Turkey on Sunday, where it will be unloaded.

Germany has been a strong advocate of sanctions against Syria amid a violent crackdown by President Bashar Assad's government on the country's uprising. The 27-nation European Union has imposed an arms embargo among other measures.

Earlier on Saturday, human rights group said Syrian forces shelled two central districts in the battered city of Homs, the first bombings since a ceasefire took hold on Thursday.

"There was shelling last night in the old part of the city, in Jouret al-Shiyah and al-Qaradis. And I have heard eight shells fall in the past hour," Karm Abu Rabea, a resident activist who lives in an adjacent neighborhood, said on Saturday morning.

The British-based Syrian Observatory for Human Rights said that shelling had wounded several people overnight.

On Friday, Syrian forces used live fire, tear gas and clubs to beat back tens of thousands of protesters who took to the streets across the country in powerful and often jubilant displays of defiance. But at that time the UN-brokered truce largely held up without the widespread, bloody offensives that have pushed the nation toward civil war.

Activists said security forces killed at least six people, a lower-than-usual toll. The rallies, described as some of the largest in months, stretched from the suburbs of Damascus to the central province of Hama, Idlib in the north and the southern province of Daraa, where the uprising began in March 2011.