The number of tankers transiting the Strait of Hormuz fell in the past day to the lowest level in two months, shipping data shows, as renewed strikes between the US and Iran and attacks on vessels heightened safety concerns, Reuters reports.

Shipping industry sources said vessels were increasingly switching off their public AIS tracking transponders, making it difficult to determine the full number of ships crossing the waterway.

Based on available data, oil and gas tanker traffic fell to its lowest level since May 25, according to analysis from Kpler.

“Should the renewed escalation in the strait lead to another prolonged closure of Hormuz, the world will find itself in a much tougher spot,” ship broker Gibson said in a report.

“With global inventories rapidly depleted in recent months, this is a recipe for much tighter supply, higher prices and significant downside risk for tanker markets.”