UK Muslims cannot understand why PM Tony Blair has not called for a ceasefire in the Middle East conflict, a leading Muslim Labour MP has said.
British Muslims want an immediate ceasefire, Mr Khan said
Writing in the Guardian, Sadiq Khan said it was "not easy" for Muslims to watch "destruction wreaked in Lebanon".
The MP for Tooting said he was worried British foreign policy could be perceived as anti-Muslim.
Mr Blair has said that moves towards stopping the violence need to be brought forward on an "urgent basis".
Israeli military action has mainly targeted Hezbollah positions in the minority Shia Muslim areas of the country.
The UN has called for a three-day truce between Israel and Hezbollah to allow for aid to enter southern Lebanon and for casualties to be removed.
US President George W Bush and Mr Blair have dismissed calls for an immediate ceasefire, arguing instead for an international force to be deployed in Lebanon to bring about an end to the violence.
Mr Khan told BBC Radio 4's Today programme: "What we can't do is wait to call for an immediate ceasefire until one side in the conflict has achieved all its military objectives.
"In the meantime, women, children, men, civilians are dying.
"There are obligations upon countries who sign international conventions to not stand by sitting on their hands, but also with their tongues tied whilst these atrocities take place."
Hezbollah had "acted probably in breach of international law as well by killing dozens of innocent Israeli civilians", but Israel must defend itself in a "proportionate manner", he said.
"We find it difficult to understand why our government has steadfastly supported the US in giving a green light to Israel," Mr Khan also wrote in the Guardian.
He said Mr Blair had "lost his way" on the Middle East.
"British foreign policy is not anti-Muslim but that is, increasingly, a challenging argument to make."
Israeli medics remove a motorist killed by a Hezbollah rocket in Haifa from his car
Muslim peer Baroness Uddin told Today she thought the majority of people in the UK - "not just Muslims" - were opposed to Mr Blair's stance on the Middle East crisis.
A spokesman for the Israeli Embassy in London told the BBC News website: "Israel has been attacked unprovokedly by Hezbollah and is responding to that threat.
"We want a ceasefire but it must be a durable and a sustainable one.
"We can't go to the situation as it was before the outbreak of the hostilities."
An immediate ceasefire without "a diplomatic solution" would not be a lasting one, he said.
Speaking at a White House press conference after his meeting with Mr Bush on Friday, Mr Blair said: "We feel deeply for people in Lebanon and people in Israel who are the innocent casualties of this conflict, of course we do.
"And we want it to stop, and we want it to stop now.
"What we are putting forward today is actually a practical plan that would lead to a UN resolution...[to] put in place the conditions for it to stop."
Some 600 Lebanese, the majority civilians, are confirmed killed in the conflict.
Fifty-one Israelis, including at least 18 civilians, have been killed, mostly by Hezbollah rockets.
The Israeli assault began after Hezbollah captured two Israeli soldiers and killed eight in a cross-border raid on 12 July.