KABUL, Afghanistan -- A German woman and an Afghan security guard were killed late Saturday night and a Finnish woman was kidnapped from a Kabul guesthouse, authorities said Sunday.

Deadly attacks also unfolded further south. In southern Afghanistan, militants launched attacks on several check points, killing at least 20 security forces, a provincial official said.

Najib Danish, deputy spokesman for the Interior Ministry, said the killings of the German woman and Afghan guard took place at 11:30 p.m. local time Saturday. There was no immediate claim of responsibility for the attack or the kidnapping. He said Kabul police started an investigation and told CBS News that a search operation is underway for the kidnapped Finnish woman.

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Danish said that the two women were working for Operation Mercy, a Sweden-based international development and relief organization.

The German Foreign Office confirmed that a German citizen was killed in Kabul but declined to identify her or provide details on how she was killed. Karoliina Romanoff, spokeswoman for Finnish Foreign Ministry, confirmed that a Finnish citizen was kidnapped but had no details. The Foreign Ministry said in a statement it demands "the immediate release of the kidnapped person."

Scott Breslin, a worker at Sweden-based organization Operation Mercy, told Swedish news agency TT that one of its workers was missing and that the organization was holding a crisis meeting.

Gul Islam Seyal, spokesman for the provincial governor in Zabul province, said Sunday that battles that killed at least 20 security forces began late Saturday when dozens of Taliban fighters launched coordinated attacks on security posts in the Shah Joy district. At least 10 other security forces, including national and local policemen, were wounded, he said.

Seyal said the Taliban also fired several rounds of mortars on Qalat, the provincial capital.

Qari Yusouf Ahmadi, a Taliban spokesman, said in a statement the group was responsible for the attacks. He confirmed that Taliban fighters overran police check points in Shah Joy and fired mortar rounds on the police chief's office in Qalat.

The Taliban have stepped up attacks against Afghan security forces across the country since announcing their spring offensive last month.