A Guyanese army helicopter with seven people on board has gone missing near Guyana's border with Venezuela as tensions escalate in a territorial dispute over the region of Essequibo, officials said.

So far, however, authorities have stressed that bad weather rather than hostile fire is the most likely cause of the aircraft's disappearance.

What do we know so far?

The helicopter was taking five senior Guyanese officers to inspect troops guarding the border area that both countries claim as their own, according to Brigadier General Omar Khan, chief of the Guyanese army.

He said two crew members were also on the aircraft, a brand new Bell 412 EPI, which vanished about 48 kilometers (30 miles) east of the Venezuelan border. 

Khan told reporters there were no indications that Venezuela was involved in the incident, despite the recent build-up of Venezuelan troops with heavy equipment and machinery at the border.

"We do not have any information suggesting that there was any flight by Venezuelan aircraft in that area," he said. "Speculation is not what I want to go into. Our priority is to save the lives of our officers and ranks."

Khan said that the US would help in the search for the aircraft on Thursday.

What is the reason for the dispute?

Guyana and Venezuela are at loggerheads over the mineral- and oil-rich Essequibo region. 

Caracas claims that the region has belonged to Venezuela since at least 1777, when the country was under Spanish rule, which began in 1522 and ended in 1811. Georgetown says the correct border was defined by international arbitrators in 1899.  

In a referendum on Sunday, Venezuelans backed President Nicolas Maduro's claims of sovereignty over Essequibo, which makes up some two-thirds of Guyanese territory. On Tuesday, Maduro said he would approve operating licenses for exploration and exploitation in the region. 

The long-running dispute has intensified since ExxonMobil discovered oil off the coast of Essequibo in 2015.

Litigation is pending before the International Court of Justice (ICJ) in The Hague over where the region's borders should lie.

The US State Department has said that in talks with Guyanese President Irfaan Ali late on Wednesday, Secretary of State Antony Blinken reaffirmed Washington's unwavering support for Guyana's sovereignty.

tj/nm (AFP, AP, Reuters)