1.   But the government has only limited power over the many Yemeni tribes, who still associate foreign powers with danger.

2.   A Chinese engineer kidnapped by a Yemeni tribe more than three weeks ago was released unharmed on Thursday, security officials said.

3.   An American engineer was kidnapped by a Yemeni tribe last month and was released unharmed after two weeks of negotiations between the tribesmen and the Yemeni government.

4.   An American engineer was kidnapped by a Yemeni tribe last month and was released unharmed after two weeks of negotiations.

5.   But a second Dutchman, Clemens Verweij, is still being held hostage by another Yemeni tribe, the Dutch Foreign Ministry said in The Hague Friday.

6.   Each case involved a different Yemeni tribe.

7.   Yemeni tribes frequently have kidnapped foreigners to press for money or government financing of projects.

8.   Yemeni tribes frequently kidnap foreigners to press for money or government financing of projects.

9.   Yemeni tribes frequently kidnap tourists, oil workers and diplomats in a bid to extort money or government funds for local projects.

10.   Yemeni tribes have frequently kidnapped foreigners to press for money or government financing of projects.