By Moabi Phia GABORONE, March 19 (Reuters) - Botswana has tightened its border controls in response to political unrest in neighbouring Zimbabwe that it fears could lead to a renewed flood of illegal migration, a senior police spokesman said on Monday. Border officers in Botswana have been told to more carefully check those entering or seeking to remain in the southern African nation and ensure they have enough money for their stay, the government said in a statement. The order came after a high-level meeting on Friday between police and immigration officials. The statement referred to the need to keep "undesirable people" out of the country, but it did not specifically mention that Zimbabweans would be the targets of the tighter controls. A senior police spokesperson told Reuters on condition of anonymity that the government had acted because of rising tensions in Zimbabwe, where police recently arrested dozens of opposition members at a protest against President Robert Mugabe. Many of the anti-Mugabe protesters, including the leader of the main opposition party, said they were beaten in police custody. The crackdown prompted widespread international condemnation of Mugabe and threats of additional sanctions. Relations between Botswana and Zimbabwe have been chilly since the government in Gaborone began constructing a three-metre-high electric fence on the border in a move it said was meant to control the spread of foot-and-mouth disease. Many Zimbabweans believe the fence, which is designed to span some 500 km, is intended to stop the flow of illegal immigrants into Botswana, a diamond-rich nation that is among the most prosperous and politically stable in Africa. Botswana and South Africa attract the lion's share of immigrants from Zimbabwe, which is struggling with inflation over 1,700 percent, an unemployment rate of 80 percent and chronic food and fuel shortages. Botswana deported more than 56,000 Zimbabweans last year, according to government statistics. "We are encountering problems of prohibited immigrants, forged travelling documents, stamps and other immigration documents," Deputy Police Commissioner Kenneth Kapinga, who attended the meeting on Friday, said in a statement.
