Christina Meier, 31, who was working for aid group Ora International in Afghanistan, arrived Monday in the German Embassy in Kabul after she was freed by Afghan police, security and intelligence agents, the online version of German news magazine Der Spiegel said Monday. The mission, which included 300 security agents, culminated in the arrest of four men.

The woman was kidnapped while eating at a restaurant in Kabul -- it was the first kidnapping in the Afghan capital in two years, and officials said it was criminally motivated.

The kidnappers at first asked for $1 million in ransom but later lowered their demand to $300,000, Spiegel Online said. The kidnappers apparently acted carelessly: Because they called from their cell phone, security officials were able to locate them. The German woman is well, officials said.

“I want to thank the Afghan security officials,” German Foreign Minister Frank-Walter Steinmeier told reporters. “The arrest mission came at exactly the right time.”

Germans have been increasingly targeted in Afghanistan in recent months.

On July 18 two German engineers working on reconstruction projects were kidnapped in Wardak province, southwest of the capital Kabul. One of them died two days later; his kidnappers pierced him with gun bullets after he had collapsed. The remaining man still is in captivity.

"It is a strategy of the Taliban to target journalists and foreigners from the West as a way to exert pressure on governments (in Europe)," Michael Lueders, a German Afghanistan expert, said recently. "The aim of the kidnappers is to end the Western engagement in Afghanistan. ... It is very clearly an 'Iraqization' of the situation in Afghanistan."