In addition to the sortie of the 16th April, Sir Sidney Smith kept the besiegers constantly on the alert by landing parties from the ships' boats on the flanks of their lines of trenches. The attacks were sometimes pushed home, the earthworks were overthrown, the fascines carried off for use in the redoubts, guns spiked, and intrenching tools captured, and these attacks greatly added to the labour imposed upon the besiegers, who were compelled not only to keep strong bodies in the advanced trenches but to defend the whole line of attack against flank surprises by their enterprising foes.