Two men have been arrested after packages containing liquid were sent to a number of hospitals across the UK, the Met Police has confirmed.
The force said a 29-year-old man from Brent and a 37-year-old man from Harrow, both in north-west London, were arrested by counter-terror officers on Thursday on suspicion of Malicious Communications Act offences.
None of the packages has so far been found to contain anything hazardous.
The men were bailed until late August.
Inquiries are continuing, the Met added.