Six activists from the environmental pressure group Greenpeace scaled a tower close to the Lisbon venue of a weekend EU-Africa summit where they unveiled a giant banner to denounce deforestation.

The giant red and green-lettered banner, which read "Save the Climate — Save the African Forests", was unfurled at the Vasco da Gama tower next to a giant exhibition hall where the two-day heads of state gathering begins on Saturday.

It took the activists some two hours to scale the 145-metre (475-ft) tower and then unfurl the banner measuring nine by 30 metres.

Greenpeace spokesman Stephan Van Praet said the leaders meeting in Lisbon should commit themselves to measures to put an end to deforestation in Africa, arguing that it is a major factor in climate change.