Russia has stepped up its assaults on Black Sea port infrastructure and civilian shipping in recent days, in what Ukraine says is an attempt to disrupt its exports and damage its economy.

The attacks are part of an intensifying campaign of strikes on the city of Odesa and the region along Ukraine’s southern coast. Since last Monday, Russia has carried out five attacks in the area, killing 14 civilians and injuring 28, the U.N.’s Human Rights Monitoring Mission in Ukraine reported on Friday, citing local authorities.

The latest strike came in the early hours of Friday, when ballistic missiles targeted the region. One of them hit a two-story residential building, killing four people, including a teenage girl, emergency services said. Another nine people were hospitalized.

The strikes on ships were mostly aimed at those flying flags of small countries unlikely to retaliate against Russia. Last Monday, a container ship under the flag of Palau was hit, Ukrainian official said. The day before that, a missile damaged a vessel under a Saint Kitts and Nevis flag, according to the regional military administration.

The recent strikes on commercial ships have prompted Peter Stano, the European Commission’s main external affairs spokesman, to accuse Russia of continuing to weaponize food shipments from Ukraine. “Russia is directly targeting the supply of food to the people most in need,” he said at a news briefing on Thursday. “All these acts are blatant violations of international law and must stop immediately.”