They hold the crews hostage with machine-guns and semi-automatic pistols, then force the captain to anchor off the northern part of Somalia’s coast for several weeks until a ransom is paid.

他们用机枪和半自动手枪挟持船员作人质，然后逼迫船长在索马里海岸北部抛锚数周直到收到赎金。

youdao

Attackers fired machine guns at the convoy.

袭击者们向护运车队开机枪。

《柯林斯英汉双解大词典》

They captured three machine guns.

他们缴了三挺机枪。

《新英汉大辞典》

The pirates have machine guns and rocket-powered bombs.

VOA: special.2009.05.27

Authorities say they quickly killed two of the gunmen, but two others continued to fire machine guns in the extended battle in Pul-i-Alam, Witnesses say U.S.military helicopters were part of the response force, and one aircraft fired a rocket into a multi-story building which the insurgents had seized, used to launch their attack and had rigged with explosives.

VOA: standard.2009.08.10

Officers armed with machine-guns and wearing balaclavas broke down a heavy wooden front gate and abseiled from a helicopter to gain entry to the property, media reports say.

BBC: German police target Hells Angels in large-scale raids

These men have only very light weapons - machine-guns and rocket propelled grenades - and they have no answer when government forces decide to use heavy weapons, as they appear to have done overnight.

BBC: Homs attack: BBC reporter takes in differing accounts

On that morning, Staff Sergeant Romesha and his comrades awakened to an attack by an estimated 300 enemy fighters occupying the high ground on all four sides of the complex, employing concentrated fire from recoilless rifles, rocket propelled grenades, anti-aircraft machine guns, mortars and small-arms fire.

WHITEHOUSE: The White House