In a major escalation of operations in Yemen, the US military carried out more than 30 airstrikes and drone strikes on Thursday, Friday and Saturday, hitting multiple targets allegedly linked to Al Qaeda in the Arabian Peninsula (AQAP). As many as 20 people were reported killed in the attacks, which hit the southern governorates of Shabwa, Al Bayda and Abyan.

The multi-day bombardment was the heaviest so far in the undeclared US war in Yemen, which has killed or injured more than 1,700 people, including hundreds of women and children, since 2009. According to a tally maintained by the Bureau of Investigative Journalism, the US has carried out a least 390 attacks in the last eight years.

Pentagon spokesman Navy Captain Jeff Davis told reporters on Friday that more airstrikes would be forthcoming: “US forces will continue to target AQAP militants and facilities in order to disrupt the terrorist organization’s plots and ultimately to protect American lives.”

Last week’s offensive was the first major military operation by the US in the country since the raid on January 29 by US Special Forces that killed as many as 30 civilians, including 8-year-old Nawar al-Awlaki, the daughter of Anwar al-Awlaki, the US citizen and Islamist cleric assassinated by the Obama administration in 2011. The raid resulted in the death of Navy SEAL William (Ryan) Owens and left three other soldiers wounded.

President Donald Trump used the presence of Owens’ widow, Carryn Owens, at his address to a joint session of Congress last week to defend the murderous operation and promote American militarism, praising her husband as “a warrior and a hero.”

The string of attacks since January marks a definite intensification by the Trump administration of the US intervention initiated by the Obama administration. Trump’s predecessor pioneered the use of drone-fired missiles to assassinate those declared to be leaders or members of AQAP. Drones have been used to target and kill alleged terrorists in countries, besides Yemen, where the US is waging war without congressional authorization, including Pakistan, Somalia, Syria and much of North Africa.

Obama notoriously claimed the right to assassinate American citizens and anyone else he chose, beginning with the murder of Anwar Al-Awlaki in September 2011. His drone killing program and war in Yemen have now passed into the hands of Trump.

The intensification of US military operations in southern Yemen comes amidst an ongoing aerial onslaught and naval blockade by a coalition led by Saudi Arabia against Houthi rebels in the country’s more populated western region.

The air campaign and subsequent ground invasion aim to push back the Houthi rebels, who took over much of the country in early 2015, and reinstate the US-backed government of President Abd Rabbu Mansour Hadi. The Saudi Arabia and its Persian Gulf allies have been funneling weapons and money to Sunni militias, including those affiliated with AQAP, to serve as ground troops in the war against the Zaidi Shiite Houthis.

Since it began in March 2015, the Saudi-led campaign, made possible by continuous support from the US government in the form of intelligence, logistics, military equipment and aerial refueling, has killed more than 10,000 Yemeni civilians and wounded 40,000. Saudi bombs have hit hospitals, schools, marketplaces, factories and residential neighborhoods.

The war has plunged the poorest country in the Middle East into a humanitarian disaster, with the UN estimating that at least 19 million Yemenis, more than two-thirds of the country’s population, are in need of assistance and protection.

UN Relief Coordinator Stephen O’Brien reported on Friday that 500,000 children under the age of five are suffering from severe acute malnutrition and more than 7 million Yemenis did not know where they would get their next meal. Even though the country risks being pushed into famine without immediate action, O’Brien reported that the UN had received only 3 percent of the estimated $2.1 billion needed to provide humanitarian assistance to 12 million people over the next year.

While Yemen is one of the poorest countries in the world, it is of considerable geopolitical significance, forming the eastern side of the Bab El Mandeb Strait, a major shipping lane which connects the Red Sea to the Gulf of Aden and the Indian Ocean. A significant portion of the world’s oil supply traverses the strait, making it one of the most important strategic choke points on the planet.

The US Navy announced last month that the USS Cole would join three other warships already operating off the coast of Yemen in the Red Sea and the Bab El Mandeb, out of “concern for the freedom of navigation.”