By Mathew Cohen Venezuela's coast guard vessels allegedly entered Guyanese waters on March 1, approaching an ExxonMobil production vessel in the disputed offshore region, Guyana's President Irfaan Ali has announced.

The Venezuelan patrol ship that entered Guyana’s waters Saturday and positioned itself near a vessel contracted by Exxon Mobil Corp. in the Stabroek oil block has departed the area, according to the Guyana Defence Force.

The South American neighbours are involved in a long-running dispute about which country owns the oil-rich Essequibo area Guyanese President Irfaan Ali said on Saturday that a Venezuelan naval vessel had entered his country's waters earlier in the day,

Guyana’s government said Saturday that a Venezuelan naval patrol ship entered its waters and approached a vessel contracted by Exxon Mobil (NYSE:XOM) in the Straboek block, according to media reports.

Guyanese President Irfaan Ali said on Saturday that a Venezuelan coast guard patrol entered Guyanese waters earlier in the day, approaching an output vessel in an offshore oil block managed by Exxon Mobil .

Guyana and Venezuela have seen heightened tensions over control of the disputed Essequibo territory, a sprawling region rich in natural resources