(CNN)-- The escalating attacks in the Gulf over the past two days, along with US President Donald Trump's threats to reimpose a US-led naval blockade, are pushing Iran to quickly remove its oil tankers from the Strait of Hormuz.

Iran shipped 10 million barrels of crude oil and fuel overnight, according to TankerTrackers, a company specializing in maritime shipping tracking. This represents a significant increase: before Thursday, Iran had managed to export a total of 60 million barrels of oil over the past three weeks, according to Windward Intelligence.

On Wednesday, tanker operators backed off from entering or leaving the strait, as uncertainty over the military situation brought many ships to a halt, and the number of transits through the Strait of Hormuz fell to 25 on Wednesday, compared to 49 the previous day, according to MarineTraffic.

Part of the reason for this decline in transit traffic on Wednesday was concern that ships entering the area could be stuck there. Most transits on Wednesday were from west to east (i.e., leaving the Gulf).

With the exception of the United Arab Emirates - which shipped up to 65 million barrels of oil after the strait reopened - Iranian exports have surpassed those of all other oil producers, and the Iranian regime gets 50% of its revenue from oil sales, which are crucial for reviving the country's post-war economy.

The reimposition of US sanctions on Iranian oil on Tuesday does not appear to deter China from buying, as according to Windward Intelligence, despite a shadow fleet of tankers, 32.3 million barrels of Iranian oil are currently heading to China.