B razil has said that it is deploying troops along its border with Venezuela after the Venezuelans announced plans to incorporate an oil-rich area of Guyana into their territory. The Essequibo region has been in dispute since the 19th Century when Guyana was a British colony. Venezuela renewed its land claims after offshore oil and gas reserves were discovered a few years ago. Tensions have been rising since a referendum on Sunday in Venezuela. More than 95% of voters are said to have supported the government's claim to Essequibo. Venezuela's leader Nicolás Maduro has since asked the state oil company to issue extraction licenses there and proposed that the National Assembly pass a bill to make the area part of Venezuela. The measures are cause for concern across the region. While Guyana has its troops on high alert, the Brazilian army has said that it is moving more soldiers to the border city of Boa Vista, the capital of Roraima state, as well as bringing in more armed vehicl...