Israel has kept up its air and naval bombardments of the Gaza Strip for a seventh day, despite growing international pressure for a ceasefire.

At least 176 people, including 29 children, have been killed as of Monday and more than 1,200 people have been wounded.

The European Union said it was in touch with "all parties in the region" to press for an immediate halt to the hostilities, a day after US Secretary of State John Kerry offered to help secure a Gaza truce.

Egypt and Qatar are seen as potential mediators but peace efforts were complicated by Hamas' rejection of a mere "calm for calm" in which both sides hold their fire in favour of wider conditions including prisoner release and an end to Israel's Gaza blockade.

Israeli Radio, quoting Egypt's state-news agency, said on Monday that Kerry will arrive in Cairo on Tuesday to discuss a ceasefire.